Process for recovery of hydrocarbons and rejection of sand

ABSTRACT

A process for recovering a hydrocarbon from a hydrocarbon bearing sand comprising the steps of mixing a chemical additive with a chemical composition and with a hydrocarbon bearing sand containing hydrocarbon and residual solids including clay, at a temperature to form a slurry. The chemical composition comprises an aqueous phase and a minor amount of a chemical agent selected from the group consisting of at least one ethoxylated alkylphenol compound, at least one ethoxylated dialkylphenol compound, MIBC, SC-177, Petronate HL, Clacium Lignosulfonate and mixtures thereof. The slurry is aerated to produce essentially sludge-free tailings and a mixture of hydrocarbon, aqueous phase and residual solids including clay. The process further comprises the step of separating the mixture of the hydrocarbon, the aqueous phase and the residual solids including clay from the essentially sludge-free tailings.

This is a continuation-in-part application of copending applicationentitled "A Process for Producing Bitumen" having Ser. No. 07/341,772filed Apr. 21, 1989 (now U.S. Pat. No. 5,083,613), which copendingapplication is a continuation application of application entitled "AProcess for Preparing a Coal-in-Aqueous Phase Mixture" having Ser. No.311 133, filed Feb. 14, 1989 (now abandoned), which application withSer. No. 311,133 being a continuation-in-part application of applicationentitled "Surfactant Requirements for the Low-Shear Formation of WaterContinuous Emulsions from Heavy Crude Oil" having Ser. No. 218,840,filed Jul. 14, 1988 (now U.S. Pat. No. 5,000,872). The applicationhaving Ser. No. 218,840, filed Jul. 14, 1988, is a continuation-in-partapplication of application entitled "Preparation of Improved StableCrude Oil Transport Emulsions" having Ser. No. 114,204, filed Oct. 17,1987 (now U.S. Pat. No. 4,978,365). The application having Ser. No.114,204, filed Oct. 27, 1987, is a continuation-in-part application ofapplication Ser. No. 934,683, filed Nov. 24, 1986, now U.S. Pat. No.4,725,287. Benefit of the earliest filing date is claimed with respectto all common subject matter. All of the immediate foregoingapplications and patents are fully incorporated herein by referencethereto as if repeated verbatim immediately hereafter.

FIELD OF THE INVENTION

present invention is related to the recovery of hydrocarbon or bitumenfrom tar sands. More particularly, the present invention provides aprocess for recovery of hydrocarbon or bitumen from tar sands as aconcentrated bitumen stream (i.e. about 10% by wt. bitumen with theremaining portion being predominately water) and the rejection of sandfrom the tar sands. The present invention further provides for theproduction of hydrocarbon or bitumen from tar sands at the mininglocation and for the disposal of the recovered sand also at the mininglocation.

BACKGROUND OF THE INVENTION

Tar sands, which are also known as oil and bituminous sands, aresiliceous materials which are primarily silica (e.g., sand grains)having closely associated therewith an oil film. Tar sands generallycomprise from about 5 to 21 percent by weight of an oil film; from about70 to about 90 percent by weight of mineral solids; and from about 1 toabout 10 percent by weight of an aqueous phase (i.e., water). The oil isvery viscous, having an API gravity of about 1 to about 10 API degreesgravity, and typically comprises from about 1.0 to about 10.0 percent byweight inorganic elements (e.g., sulfur) and from about 30.0 to about50.0 percent by weight cyclic hydrocarbons such as aromatics. The term"solids" is used herein to describe material of inorganic origin such assand, clay and the like, as distinguished from materials of organicorigin such as coke. The major portion, by weight, of the mineral solidsin tar sands is quartz sand having a particle size greater than about 40microns and less than about 2000 microns. The remaining mineral solidmaterial found in tar sands has a particle size of less than about 40microns and has been generally referred to as "fines". Fines compriseclay and silt including some very small particles of sand. Clay is ahydrated aluminum silicate with a generalized formula Al₂ O₃ SiO₂.xH₂ O.More specifically, it has properties of fine, irregularly shapedcrystals and depending on the iron oxide content, it has a specificgravity of from about 2.3 to about 2.7. Types of clay are kaolinite,montmorrillonite, illite, bentonite, attapulgite, and halloysite. Thefines content will vary from about 5 percent to about 35 percent byweight of the total mineral solid content of tar sands. It is to beunderstood and is not uncommon for the ingredients of tar sands to varyfrom the stated proportions and concentrations.

Canada has the potential to be self-sufficient in petroleum and could bein a very enviable position. To attain self sufficiency with her energyrequirements increasing and conventional petroleum reserves decreasingannually, development of energy sources, such as the oil or tar sands,becomes essential. Major impediments to current development ofconventional oil sands plants are the large capital investmentrequirement estimated to range from $35,000 to $45,000 per daily barrelof plant capacity and the concomitant operating costs associated withmining, extraction and upgrading of bitumen to saleable synthetic crudeor transportation fuels. Equally important in the production ofsynthetic crude oil from oil sand by conventional first generationextraction technology is the large quantity of waste water and sludgeproduced which are likely to be unacceptable in future plants. Forexample, in the first 10 years of operation at a well known facility,the volume of waste water containment which stores process affectedwater, waste, process chemicals and sludge grew to about 215×10⁶ m³ andcovers an area of 22 km². (see "Development of the Tailings Pond atSyncrude's Oil Sands Plant; 1978-1987," M. D. MacKinnon, AOSTRA Journalof Research, 5 (1989) pg. 109.) Future liabilities related toenvironmental issues and specifically waste water containment may alsoadversely affect future participation by industry.

The largest and most important deposits of tar sands are the Athabascatar sands, found along the banks of the Athabasca River in the Provinceof Alberta, Canada. Total recoverable reserves from the Athabasca tarsands, after extraction and processing, have been estimated at more thanabout 300 billion barrels. Athabasca tar sands comprises sand grainswhich are each sheathed in a thin layer of aqueous phase (i.e. water).Bitumen is trapped in the void space between the water-wet grains. Thecomposition of Athabasca tar sands may typically comprise from about 5to about 15 percent by weight bitumen, from about 1.0 to about 10.0percent by weight water, and from about 80.0 to about 90.0 percent byweight of solids (as defined above). While the present invention will bedescribed with reference to Athabasca tar sands as a feed stock, it isto be understood that the spirit and scope of the present inventionincludes any hydrocarbon bearing sand as feed stock.

Presently known commercial arrangements include the existing Syncrudeand Suncor operations in Alberta, Canada. Both operations employ drymining of tar sands, which broadly comprises transportation of thismaterial to extraction plants located distally, separation of a largesand fraction from the tar sands, and slurry transportation of thereject sand-clay-silt stream to a distal tailings pond. A simplifiedflow process of the Syncrude operations broadly involves mining, tarsands transportation, followed by primary separation which incorporatestumblers, thickeners and flotation vessels. The tailings are slurriedback to an ever-increasing pond due to the physical and chemicalcharacteristics of the sands and sludge.

Athabasca tar sands are presently and more specifically processed usinga method which is commonly referred to as the "hot water" method. Inaccordance with the "hot water" process for primary extraction ofbitumen from tar sands, tar sand is mixed in a conditioning drum ortumbler with hot water and steam. Sodium hydroxide or other reagents areadded as required to maintain and control the pH in the range of fromabout 8.0 to about 8.5. While in the tumbler, the tar sandsdisintegrates and liberates bitumen, and simultaneously, liberatedbitumen is aerated. By "disintegrate" is meant that the bitumenparticles and particulate sand are dispersed or separated from eachother in a preliminary manner or fashion. Stated alternatively, duringslurrying bitumen films are ruptured and a preliminary separation of thesand grains and bitumen droplets takes place. Simultaneously, airbubbles are entrained in the slurry. The tumbler produces a pulp orslurry having the consistency of porridge or leek soup or broth, andcomprising from about 5.0 to about 15.0 percent by weight bitumen, fromabout 15.0 to about 30.0 percent by weight water, and from about 60.0 toabout 80.0 percent solids (as defined above), at a temperature of180°-195° F.

The produced conditioned pulp or slurry leaves the tumbler and is thendiluted with additional hot water to further disperse the sand andbitumen. This dilution operation is usually carried out at a screenpositioned at the outlet from the tumbler. The diluted or flooded slurrytypically has a composition comprising 2 to 10 wt. percent bitumen, 40to 50 wt. percent water, and 45 to 55 wt. percent solids ( as definedabove).

The diluted or flooded slurry is subsequently introduced into aseparator cell in proximity to its longitudinal point. The separatorcell is typically a cylindrical vessel having a conical bottom. Thecontents of the separator cell are commonly maintained at about 75° to85° C. In the separator cell the bitumen particles, which have beenattached to air bubbles, tend to rise to the surface of the water bodyand form a coherent mass known as an oily primary froth which forfurther treatment is recovered in a launder running around the rim ofthe cell. The major portion of the solids, particularly the coarse sandparticles, tend to sink to the bottom of the cell and are withdrawn ordrawn off as tailings.

A middlings stream comprising water, fine solids (e.g., clay) and someoil or bitumen, is continuously withdrawn from the separator cell at apoint intermediate to the upper and lower ends of the separator cell.This middling stream typically comprises from about 1 to about 4 percentby weight bitumen, from about 10 to about 20 percent by weight mineralsolids, and from about 75 to about 90 percent by weight aqueous phase orwater. This middling stream is treated in a sub-aerated flotation cellto recover the contained bitumen in the form of secondary froth. Thesecondary froth is badly contaminated with mineral solids and water andmay typically comprise 12 to 20 percent by weight solids, 50 to 60percent by weight aqueous phase (or water) and 25 to 37 percent byweight bitumen. Once the bitumen has been extracted from the tar sand inthis fashion, the primary and secondary froths are combined, dilutedwith a specific gravity-altering diluent (such as naphtha or any othersuitable agent) and treated in a centrifuge circuit to separate thesolids or residual minerals and water from the bitumen. The specificgravity-altering diluent (i.e., naphtha) may be distilled for furtherprocessing. The following patents broadly teach or suggest an apparatusand/or method for removing bitumen from tar sands, with some of thefollowing patents more specifically teaching the caustic "hot water"process: U.S. Pat. Nos. 3,068,167 to White; 3,297,568 to McMahon;3,392,105 to Poettmann et al; 3,696,923 to Miller; 3,864,251 toCymbalisty; 3,869,384 to Schutte; 4,018,664 to Bain et al; 4,229,281 toAlquist et al; 4,340,487 to Lynn; 4,368,111 to Siefkin et al; 4,392,941to Roth et al; 4,514,305 to Filby; 4,891,131 to Sadeghi et al; 4,913,805to Chin; 4,946,597 to Sury; 4,968,412 to Guymon; 5,009,773 to Schramm etal; 5,019,245 to Ignasiak et al; 4,036,732 to Irani et al; 4,071,434 toGifford; 4,110,194 to Peterson et al; 4,347,118 to Funk et al; 4,383,914to Kizior; 4,399,039 to Yong; 4,424,112 to Rendall; 4,676,889 to Hsiehet al; 4,702,487 to Stoian et al; 4,719,008 to Sparks et al; 4,776,949to Leung et al; and 4,929,341 to Thirumalachar et al. All of these U.S.Patents will be fully incorporated herein by reference thereto as iffully repeated verbatim immediately hereafter.

Conventional extraction processes result in a significant quantity oforganic and inorganic sludges remaining with the reject tailings. Thisstrongly bound (toluene insoluble) organic matter modifies thehydrophilic character of certain oil sand solids resulting in seriousproblems in processing oil or tar sands in conventional hot waterextraction processes. ("Properties of Fines Size Fractions in Relationto the Distribution of Humic-Inorganic Matter Complexes in Athabasca OilSands," L. S. Kotlyar and B. D. Sparks, AOSTRA Journal of Research, 4(1988) pg. 277.) These compounds also complicate the operation of thetailings pond by remaining in suspension as "globules." It has beenreported that one half of the silt and clay and almost all the bitumenremains in suspension and flows to the center of the pond to form asludge containing up to 85 to 90% process water.

Speight and Moschopedis presented results of studies addressing claysremaining in pond water in the form of a colloidal dispersion whichadversely affects the volume of water available from the pond forrecycle. Variation of pH causes a change in the charge on the surfacesof clay particles, thus effecting flocculation. (see "Factors AffectingBitumen Recovery by the Hot Water Process," J. G. Speight and S. E.Moschopedis, Alberta Research Council, 1978.) They further conclude thatthe disposal of tailings from the hot water extraction processrepresents one of the major problems facing commercial development.While surface active materials present in the bitumen appear to have abeneficial effect on bitumen recovery, their ability to act as claydispersants has an adverse effect on the settling of the clays in thetailings pond. (see "Surface and Interfacial Phenomena Related to theHot Water Processing of Athabasca Oil Sands," J. G. Special and S. E.Moschopedis, Alberta Research Council, Information Series 86, 1980).

Bowman and Co-workers (J. Leja and C. W. Bowman, "Application ofThermodynamics to the Athabasca Tar Sands", Can. J. Chem. Eng., A6(1968) pg. 479) established that the surface active agents in theprocess are primarily water soluble salts of naphthenic acids havingcarboxylic functional groups. Furthermore, they observed that thesurfactants interact with mineral surfaces and play a role in solidsflotation.

Sanford and Co-workers concluded that the role of sodium hydroxide inthe hot water extraction process is primarily that of a generator ofnatural surfactants which in some way aid oil separation and/orflotation. A further finding and of equal importance was the relationbetween the fines level and the caustic needed for oil recovery.Furthermore, very lean grades of oil sands may not be able to supplyenough surfactant, adversely affecting bitumen recovery. (L. L. Schramm,R. G. Smith J. A. Stone AOSTRA Journal of Research, Vol. 1, 1984; page10).

Schramm and Smith conducted extensive testing to determine the adverseaffects that aging of tar sands had on bitumen recovery. They concludedthat the aging mechanism is traced to changes in natural surfactantconcentrations generated during processing. In essence they found thatthe aging effect can be traced to reactions that effectively reduce theconcentration of natural carboxylate surfactant produced in the hotwater separation process. ("Some Observations on the Aging Phenomenon inthe Hot Water Processing of Athabasca Oil Sands, Part 2, The Mechanismof Aging," L. L. Schramm and R. G Smith, AOSTRA Journal of Research Vol.3 (1987) pg. 215).

Kotlyar, Sparks and Kodama concluded that serious problems which occurduring bitumen extraction by the hot water process could be due to thefact that the hydrophilic (water loving) character of some of the solidsis modified by the presence of tightly bound organic (humic) matter.This material cannot be removed by extraction with good solventscommonly used for bitumen such as toluene or dichloromethane. Most ofthe humic matter in oil sands is known to be associated with fines i.e.,that fraction of oil sands solids with a particle size below 38 microns.(see "Isolation and Characterization of Organic-Rich Solids Present inAthabasca Tailings Pond Sludge", L. S. Kotlyar, B. D. Sparks and H.Kodaman, AOSTRA Journal of Research, Vol. 6 (1990) pg. 41).

M. D. MacKinnon addresses the development of the tailings pond at theSyncrude plant between 1978 and 1987. He indicates that about 70% of theplant water requirements are reclaimed from the free water zone and that1 m³ of water per ton of oil sand is recycled from the pond. Anadditional requirement of 0.3 m³ per ton of oil sand is withdrawn fromthe Athabasca River. Extensive information on the physical and chemicalproperties of the pond is presented. (M. D. MacKinnon, AOSTRA Journal ofResearch, Vol. 5 (1989) pg. 109-131.) Other organizations have alsoinvestigated alternative technologies for the surface minable resourcewith a view to reducing the cost of recovering bitumen from oil sands aswell as minimizing some of the problems noted.

As specifically stated in U.S. Pat. No. 4,392,941 to Roth et al, thetailings that are collected from recovering bitumen from tar sands,generally will contain solids as well as dissolved chemicals. Thetailings are usually collected in a retention pond where additionalseparation occurs. As is well known, retention ponds involve large spacerequirements and the construction of expensive enclosure dikes. Thetailings can also be considered as processing waste water containingsolids which are discharged from the extraction process. The tailingscomprise waste water, both the natural occurring water and added water,bitumen and mineral. As stated in U.S. Pat. No. 4,018,664 to Bain et al,because this waste water contains oil emulsions, finely dispersed claywith poor settling characteristics and other contaminants, waterpollution considerations prohibit discarding the effluent into rivers,lakes or other natural bodies of water. The disposal of the waste waterstreams has therefore presented a problem. A portion of the water in thewaste water stream can be recycled back into the hot water extractionprocess as an economic measure to conserve both heat and water. However,experience has shown that the dispersed silt and clay content of therecycled water can reduce primary froth yield by increasing theviscosity of the middlings layer and retarding the upward velocity ofoil droplets. When this occurs, the smaller oil droplets, and those thatare more heavily laden with mineral matter stay suspended in the waterof the separation cell and are removed from the cell with the middlingslayer.

The mineral particle size distribution is particularly significant tooperation of the hot water process and to sludge accumulation. The terms"sand", "silt" and "clay" are used in this specification as particlesize designations. Sand is siliceous material which will not passthrough a 325 mesh screen. Silt will pass through a 325 mesh screen butis generally smaller than 45 microns and larger than two microns and cancontain siliceous material. Clay is smaller than 2 microns and also cancontain siliceous material. The word "fines" as used herein refers to acombination of silt and clay.

As previously indicated and as specifically stated in U.S. Pat. No.4,392,941 to Roth et al, conditioning tar sands for the recovery ofbitumen consists of heating the tar sand/water mixture to processtemperature (180°-200° F.), physical mixing of the pulp to uniformcomposition and consistency, and the consumption (by chemical reaction)of the caustic (i.e., NaOH) or other added reagents. Under theseconditions as Roth et al points out in U.S. Pat. No. 4,392,941, bitumenis stripped from the individual sand grains and mixed into pulp in theform of discrete droplets of a particle size on the same order as thatof the sand grains. During conditioning, a large fraction of the clayparticles becomes well dispersed and mixed throughout the pulp. Theconditioning process which prepares bitumen for efficient recoveryduring the following process steps also prepares the clays to be themost difficult to deal with in the tailings disposal operation.

As further previously indicated and as specifically stated by Roth et alin U.S. Pat. No. 4,392,941, the other process step, termed "separation",is actually the bitumen recovery step because the separation has alreadyoccurred during conditioning. The conditioned tar sand pulp is screenedto remove rocks and unconditionable lumps of tar sands and clay. Thereject material, termed "screen oversize" is discarded The screened pulpis further diluted or flooded with water to promote the following twosettling processes: globules of bitumen, essentially mineral-free, floatupward to form a coherent mass of froth on the surface of the separationunits; and, at the same time, mineral particles, particularly the sandsize material, settle down and are removed from the bottom of theseparation unit as sand tailings. These two settling processes takeplace through a medium called the middlings. The middlings consistsprimarily of water, bitumen particles and suspended fines which includessilt and clay.

Roth et al in U.S. Pat. No. 4,392,941 has stated that the particularsizes and densities of the sand and of the bitumen particles arerelatively fixed. The parameter which influences the settling processesmost is the viscosity of the middlings. Characteristically, as thesuspended material content rises above a certain threshold, which variesaccording to the composition of the suspended fines, viscosity rapidlyachieves high values with the effect that the settling processesessentially stop. Little or no bitumen is recovered and all streamsexiting the unit have about the same composition as the feed. As thefeed suspended fines content increases, more water must be used in theprocess to maintain middlings viscosity within the operable range.

The third step of the hot water process is scavenging. The feedsuspended fine content sets the process water requirement through theneed to control middlings viscosity which, as noted before and asindicated by Roth et al in U.S. Pat. No. 4,392,941, is governed by theclay/water ratio. It is usually necessary to withdraw a stream ofmiddlings to maintain the separation unit material balance, and thisstream of middlings can be scavenged for recovery of incremental amountsof bitumen. Air flotation is an effective scavenging method for thismiddlings stream.

As is well known in the art, final extraction or froth clean-up isusually accomplished by centrifugation. Froth from primary extraction isdiluted with naphtha, and the diluted froth is then subjected to a twostage centrifugation. This process yields an oil product of essentiallypure, but diluted, bitumen. Water and mineral and anyunrecovered bitumenremoved from the froth constitutes an additional tailing stream whichmust be disposed.

Tailings are a throwaway material generated or obtained in the course ofextracting the valuable material (i.e. bitumen) from the non-valuablematerial (e.g. sand, sludge, etc.) And in tar sands processing, tailingsconsist of the whole tar sand plus net additions of process water lessonly the recovered bitumen product. Roth et al in U.S. Pat. No.4,392,941 has subdivided tar sand tailings into the following threecategories: (1) screen oversize; (2) sand tailings--the fraction thatsettles rapidly, and (3) middlings--the fraction that settles slowly.Screen oversize is typically collected and handled as a separate stream.

Tailings disposal is the operation required to place the tailings in afinal resting place. As previously indicated, because the tailingscontain bitumen or oil emulsions which may be defined as finelydispersed clay with poor settling characteristics and othercontaminants, water pollution considerations prohibit discarding thetailings into rivers, lakes or other natural bodies. As previouslymentioned, currently the tailings are stored in retention ponds (alsoreferred to as evaporation ponds) which involve large space requirementsand the construction of expensive enclosure dikes. As further previouslymentioned, a portion of the water in the tailings can be recycled backinto the water extraction process as an economic measure to conservewater. Roth et al in U.S. Pat. No. 4,392,941 has indicated that thefollowing are two main operating modes for tailings disposal: (1) dikebuilding--hydraulic conveying of tailings followed by mechanicalcompaction of the sand tailings fraction; and (2)overboarding--hydraulic transport with no mechanical compaction.

For dike building at a well known commercial location, tailings areconveyed hydraulically to the disposal area and discharged onto the topof a sand dike which is constructed to serve as an impoundment for apool of liquid contained inside. On the dike, sand settles rapidly and aslurry of water, silt, clay and minor amount of bitumen, as well as anychemical used during processing flows into the pond interior. Thesettled sand is mechanically compacted to build the dike to a higherlevel. The slurry which drains into the pond interior commencesstratification in settling over a time scale of months to years. As aresult of this long term settling, Roth et al in U.S. Pat. No. 4,392,941has stated that three layers form. The top layer, e.g. 5-10 feet of thepool, is a layer of relatively clear water containing minor amounts ofsol id, e.g. up to 5 wt. percent and any dissolved chemicals. This layerof pond water can be recycled to the water extraction process withoutinterfering with extraction of bitumen from tar sands. As previouslyindicated, recycling pond water serves to reduce the overall volumeincrease of water stored in retention pond. Below this clear top waterlayer is a discontinuity in solid contents. Over a few feet, solidscontent increases to about 10-15 wt. percent and thereafter, sol idacontents increase regularly toward the pond bottom. In the deeper partsof the pond, solid contents of over 50 wt. percent have been measured.This second layer is commonly called the sludge layer. In general thesludge layer can be characterized as having more than 10 wt. percentsolids (which may also be defined as mineral plus bitumen). Moreparticularly as Roth et al has stated in U.S. Pat. No. 4,392,941, thesludge can be characterized as having 20 wt. percent to 50 wt. percentsolids or mineral matter comprising substantially clay and silt. Alsothe sludge can be characterized as having about 0.5 to about 25 wt.percent bitumen. The solids contents of the sludge layer increaseregularly from top to bottom by a factor of about 4-5. Portions of thesolids are clays. The clays, dispersed by the processing, apparentlyhave partially reflocculated into a fragile gel network. Through thisgel, particles of larger-than-clay sizes are slowly settling. Generallythis sludge layer cannot be recycled to the separation step because noadditional bitumen is extracted. More specifically, sludge is notsuitable for recycling to the hot water extraction process for thereason that its addition into the separation cell or the scavenger cellat the normal inlet means would raise the mineral content of themiddlings of the cell to the extent that recovery of bitumen would besubstantially reduced. Generally, the settling which does take place inthe pond provides a body of water in which the concentration of mineralmatter increases substantially from the surface of the pond to thebottom thereof. A third layer formed of sand also exists.

Roth et al has defined in U.S. Pat. No. 4,392,941 "overboarding" as theoperation in which tailings are discharged over the top of the sand dikedirectly into the liquid pool. A rapid and slow settling process occursbut this distinction is not as acute as in the previously mentioned dikebuilding and no mechanical compaction is carried out. The sand portionof the tailings settles rapidly to form a gently sloping beach,extending from the discharge point toward the pond interior. As the sandsettles, a slurry drains into the pool and commences long-term settling.Thus water in ponds prepared by both dike building and overboarding canbe included in the general definition of sludge in the presentdescription.

As stated in U.S. Pat. No. 4,018,664 to Bain et al, experience has shownthat, as the pond forms, the various components in the effluentdischarge settle in the pond at varying rates. As an example, when thewaste water containing sand, silt, clay and bitumen is discharged to thepond, the free bitumen normally immediately floats to the surface of thepond and the sand immediately settles to the bottom of the pond.However, after the surface bitumen cools and releases the entrapped airwhich originally caused it to float, it too will begin to settle towardthe bottom of the pond. The silt and clay in the discharge settle in thepond at a substantially low rate as compared to the sand.

Bain et al has characterized a pond in U.S. Pat. No. 4,018,664 asfollows: it can be pictured as a large body of water containingdispersed solids which are slowly settling toward the bottom of thepond. The mineral matter in the pond is in a constant but slow state ofsettling. Normally, the pond is constantly increasing in size because ofthe continuous addition of waste water and therefore the character ofthe pond is continually changing.

In processing tar sands to recover bitumen therefrom, the tar sands areexcavated, extracted to remove the bitumen, whereafter the sand andother minerals are returned to the excavated area. As noted above, wastewaters associated with the extraction step must be stored in a retentionpond which is normally placed in one of the excavated areas. It isimportant that the excavated area be filled only with minerals and notwith water since obviously the water is excess and therefore requiresmore storage volume than is available. If a retention pond associatedwith the hot water extraction of bitumen from tar sands is not treatedto remove water layers which cannot normally be reused, such as sludge,the problem of a shortage of storage space is ever present.

Bain et al has further characterized a pond in U.S. Pat. No. 4,018,664as follows: a waste water retention pond associated with hot waterprocess for extracting bitumen from 140,000 to 150,000 tons of tar sandsper day and having a surface area of about 1,000 acres and an averagedepth of 40 feet can be characterized somewhat as follows:

(a) From the surface of the pond to a depth of about 15 feet the mineralconcentration which is primarily clay is found to be about 0.5 to 5.0weight percent. This pond water can normally be recycled to a hot waterextraction process without interfering with the extraction of bitumenfrom tar sands.

(b) The layer of water in the pond between 15 and 25 feet from thesurface contains between 5.0 and 20 percent mineral matter. This water,if recycled to the separation cell feed with fresh tar sands, wouldincrease the mineral content of the middlings portion of the cell to thepoint that little bitumen would be recovered.

(c) Finally, the section of the pond between 25 feet and the bottom ofthe pond contains 20 to 50 percent mineral matter and is normallyreferred to as sludge.

What is needed and what has been discovered by us is a process for therecovery of hydrocarbon or bitumen from tar sands. More specifically,what is needed and what has been invented by us is a process for therecovery of hydrocarbon or bitumen from tar sands and the rejection ofrecovered sand from the tar sands, all at the mining site. The recoveredhydrocarbon or bitumen may be upgraded by sending the same to anupgrading unit.

SUMMARY OF THE INVENTION

The present invention broadly accomplishes its desired objects bybroadly providing a process for the extraction and recovery of ahydrocarbon from water wet tar sands comprising:

(a) introducing a water wet tar sand and water into a conditioning zoneto form a tar sand slurry;

(b) agitating the formed tar sand slurry of step (a) to form an agitatedtar sand slurry;

(c) separating the formed agitated tar sand slurry to form an aeratedtar sand slurry comprising water, hydrocarbon and solids;

(d) separating in less than about five seconds essentially all of thesolids from the hydrocarbon and water of the aerated tar sand slurry toproduce a hydrocarbon and water mixture, and depositing said solids atthe mine site; and

(e) separating essentially all of the hydrocarbon from the hydrocarbonand water mixture of step (d).

The present invention further broadly accomplishes its desired objectsby further broadly providing a process for recovering a hydrocarbon froma hydrocarbon bearing sand comprising the steps of:

(a) mixing a chemical additive (e.g. kerosene and/or diesel) with achemical composition and with a hydrocarbon bearing sand containinghydrocarbon and residual solids including clay, at a temperature to forma slurry, wherein said chemical composition comprises an aqueous phaseand a minor amount of a chemical agent selected from the groupconsisting of at least one ethoxylated alkylphenol compound, at leastone ethoxylated dialkylphenol compound, MIBC, SC-177, Petronate HL,calcium lignosulfonate, and mixtures thereof;

(b) aerating the formed slurry of step (a) to produce essentiallysludge-free tailings and a mixture of hydrocarbon, aqueous phase andresidual solids including clay;

(c) separating said mixture of said hydrocarbon, said aqueous phase andsaid residual solids including clay from the essentially sludge-freetailings.

In another embodiment, the present invention yet further broadlyaccomplishes its desired objects by yet further broadly providing aprocess for recovering bitumen from tar sands comprising the steps of:

(a) mixing a chemical additive (e.g. kerosene and/or diesel) with achemical agent and with an aqueous phase with tar sands containingbitumen and residual solids including clay, at a temperature to form aslurry, wherein said chemical agent is selected from the groupconsisting of at least one ethoxylated alkylphenol compound, at leastone ethoxylated dialkyphenol compound, MIBC, SC-177, Petronate HL,calcium lignosulfonate, and mixtures thereof;

(b) pumping the formed slurry of step (a) towards at least one mixer;

(c) aerating the pumped slurry of step (b) to assist in the productionof esentially sludge-free tailings and a mixture of bitumen, aqueousphase and residual solids including clay;

(d) agitating the aerated slurry of step (c) with said at least onemixer to further assist in the production of essentially sludge-freetailings and said mixture of bitumen, aqueous phase and residual solidsincluding clay;

(e) separating said mixture of said bitumen and said aqueous phase andsaid residual solids including clay from the agitated slurry of step (d)to produce essentially sludge-free tailings; and

(f) separating said aqueous phase and said residual solids includingclay from said step (e) mixture comprising said bitumen, said residualsolids including clay, and said aqueous phase to produce said bitumen asbeing essentially free of residual solids including clay.

A major objective of the present invention is to integrate sandseparation and disposal close to or at the mining site, since materialstransportation and processing constitute a major investment andoperating cost associated with existing tar sands operations. A furtherobjective is to minimize or eliminate costly and environmentallyunacceptable tailings ponds associated with existing tar sandsoperations. More specifically, the technology of the present inventionmay employ novel surfactants in combination with cold or hot water inseparating tar sands slurry into a bitumen concentrate, a water fractionand a sand fraction in a separation process unit(s) such as ahydrocyclone or similar device. The hydrocyclone separates in less thanabout 5 seconds the solids from the hydrocarbon and water of the aeratedtar sand slurry to produce a hydrocarbon or bitumen and water mixture.All operations in the concepts of the present invention arestrategically located at the mining site. Sand is rejected at the miningsite avoiding the costs associated with transporting the mass to adistant extraction plant and subsequently returning the sand to atailings pond.

The process of the present invention minimizes investment and operatingcosts associated with transporting large quantities of solids whichcomprise 80-90 percent of the tar sands from the mining site to theextraction plant and back to a tailings disposal pond. This isaccomplished by dry or hydraulic mining of tar sands, combining requiredwater and surfactant(s), mixing in a tumbler or suitable substitute, andsending the total mix to a separation device such as a hydrocyclone. Alloperations are strategically located at the mining site. A slurryconcentrated solids stream is recycled back to an integratedmining-tailings pond wherein the sand is compacted and water is reused,if required in the process. The entire operation is located andintegrated the at the mine site using conventional mining technology,i.e., hydraulic or dry, with a slurry conditioning step in piping ormixers followed by solids-bitumen separation for rejecting a majorportion of the sand fraction in the slurry and depositing it at the minesite. Equipment employed for the latter could involve hydrocyclones,froth flotation, etc. The major component is the use of novelsurfactants or other claimed substitutes to effect the desiredwater-sand-bitumen concentrate separation. It is yet another objectiveto have the toluene insoluble organic sludges remain with theconcentrated bitumen stream to be processed in downstream equipment forbitumen recovery as well as additional solids separation. The tailingsstream will be free of this strongly bound (toluene insoluble) organicmatter in order to improve sand separation and compaction.

The concept of sand rejection at the excavation/production siteeliminates the need for transporting large quantities of materialscommonly employed in commercial processes. The use of novel surfactantsin combination with cold or hot water or brine is effective inseparating water wet sand from bitumen. A bitumen concentrate can beeffectively separated from sand at the mining site compared to analkaline treatment. The most significant aspect of this application inthe field is separating all or part of the sand at the mine from abitumen concentrate and leaving the bulk of sand at the mine site. Byminimizing the tailings transportation which consists of sand, clays,silt, and makes up approximately 90% of the tar sands, very largematerials handling investment and operating costs can be eliminated orreduced. Minimizing or eliminating conventional tailing ponds such asthose employed at Syncrude and Suncor is desirable.

The results of the present invention are totally unexpected in view ofthe published literature, for example E. C. Sandford, Syncrude CanadaLtd. in an article titled "Processibility of Athabasca Oil Sand", Can.J. Chem. Eng., V61 (1983) pg. 554, which indicates that "non-ionicsurfactants were not useful"; pg. 555 "As a general rule non-ionicemulsifiers of low HLB, such as ATPET 100, have no effect onextraction". He further shows that NP-35 results in bitumen recoverydecreasing from 65% to 10% with the addition of Tergitol NP-35. Furthertesting conducted in a laboratory apparatus substantiates that thesurfactants of the present invention (such as NP40+NP100 or, DP/DNP150)are as effective as caustic in recovering bitumen from tar sands (90+%)while producing a water clear of the suspended solids and bitumen foundwith caustic hot water treating. The results confirm that thesubstitutes to caustic of the present invention are equally effective inbitumen recovery with attendant production of clean recycled water andsands.

It is therefore an object of the present invention to provide a processfor recovering hydrocarbon or bitumen from tar sands.

It is another object of the present invention to provide a process forrecovering hydrocarbon or bitumen, from tar sands and for disposing ofthe resulting sand at the mining location.

These, together with the various ancillary objects and features whichwill become apparent to those skilled in the art as the followingdescription proceeds, are attained by this novel method for removingbitumen/hydrocarbn from tar sands, a preferred embodiment as shown withreference to the accompanying drawings, by way of example only, wherein;

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block flow diagram of a conventional caustic hot waterextraction process wherein bitumen is removed from tar sands;

FIG. 2 is a schematic flow diagram illustrating a presently preferredembodiment for recovering bitumen from sludge;

FIG. 3A is a diagram of involuted feed for a hydroclone separator FIG.3B is a diagram of tangential feed for a hydrocyclone separator;

FIG. 4 is a schematic diagram of feed entering a Krebs hydrocyclone;

FIG. 5 is a schematic flow diagram illustrating a presently preferredembodiment and best mode of a novel process for recoveringbitumen/hydrocarbon from tar sands;

FIG. 6 is a schematic flow diagram for an embodiment (i.e. ProcessOption 1) of the present invention;

FIG. 7 is a schematic flow diagram for an embodiment (i.e. ProcessOption 2) of the present invention;

FIG. 8 is a schematic flow diagram for an embodiment (i.e. ProcessOption 3) of the present invention;

FIG. 9 is a schematic flow diagram for an embodiment (i.e. ProcessOption 4) of the present invention;

FIG. 9A is a graph of bitumen extraction test results for runs 16 to 22;

FIG. 10 is a graph of bitumen extraction test results for runs 22 to 27;

FIG. 11 is a graph of bitumen extraction test results for runs 28 to 33;

FIG. 12 is a graph of bitumen extraction test results for runs 34 to 38;

FIG. 13 is a graph of bitumen extraction test results for runs 39 to 42;

FIG. 14 is a graph of the effect of temperature on separation rate(DP-DNP-150 at 600 ppm, Kero at 600 ppm);

FIG. 15 is a graph of the effect of additive concentration on separation(DP-DNP-150, 0 to 600 ppm, Kero at 600 ppm);

FIG. 16 is a graph of the effect of bitumen air and solids content onbitumen recovery; and

FIG. 17 is a simplified process flow diagram of sand reduction withbitumen/water transportation to control processing plant forconcentration and processing plant for concentration and processing.

DETAILED DESCRIPTION OF THE INVENTION

Referring in detail now to the drawings, wherein similar parts of theinvention are identified by like reference numerals, there is seen inFIG. 1, tar sands being fed into a conditioning drum (tumbler or muller)10 through line 12. Water is added to the conditioning drum 10 throughline 14, and steam is added to same through line 16. Water may includeclear recycle water passing through line 22 from a retention pondgenerally illustrated as 24. The total water so introduced in liquid andvapor form is a minor amount based on the weight of the tar sandsprocessed. More specifically, the mixture, a slurry, is about 0.3:1water to sand by mass. Caustic (e.g., NaOH) in about 1M solution isadded to the drum through line 18 to raise the pH of the slurry fromabout 7.0 or less to about 8.5. The temperature rises to about 80° C. inthis mixing process. The water film between the bitumen and the sandgrains ruptures, and small globules of bitumen froth form. The tar sandsconditioned with water, steam and caustic pass through a line 26 to athickener vessel (or primary separation tank) 28 which serves as a zonefor diluting the pulp or slurry with additional hot water via line 30.The additional hot water raises the water to initial tar sands massratio to about 1:1. In the thickener vessel (or primary separation tank)28 the heavy sand settles and is removed from the bottom of thethickener vessel 28 through line 34. A layer of frothy, impure bitumenrises to the surface and is skimmed off through line 36 which leads to abitumen separator (i.e. dilution centrifuging) 38 for separating bitumenfrom sludge. Between about 75% and 90% of the bitumen is recovered fromthe tar sands in this primary froth. The settling zone within thethickener vessel 28 is relatively quiescent so that the bitumen frothcan rise to the top of the slurry or pulp in the thickener vessel 28 tobe removed through the line 36, while the bulk of the sand (i.e. solids)settles to the bottom of the thickener vessel 28 as a tailings layerwhich is withdrawn through the line 34 and introduced into line 35.

A middlings stream is withdrawn from the thickener vessel 28 via line 40and is directed into a flotation vessel 42 where agitation and airinjection help separate the remaining bitumen as a secondary froth.Stated alternatively, in the flotation vessel 42, air is introduced intothe flotation vessel 42 through line 50 to conduct an air flotationoperation in the flotation vessel 42 and cause the formation ofadditional bitumen froth which passes out of the flotation vessel 42through a line 52, and into line 36 to be admixed with the primarybitumen froth. The combined primary and secondary bitumen froth includesremaining solids, and water, and bitumen; and the combined bitumen frothstreams is sent to the bitumen separator 38 for recovering bitumen. Abitumen-lean water and sand tailings stream is removed from the bottomof the flotation vessel 42 through line 56 to be introduced into line 35to be admixed with the tailings layer that passed through line 34.

The bitumen separator 38 is preferably a dilution centrifuging vesselwhich receives naphtha (i.e. solvent) from a line 60 that extends from anaphtha recovery system 62 to the bitumen separator 38. The naphtha isadmixed in the bitumen separator 38 with the combined primary andsecondary bitumen froth streams and assists in combination with thecentrifuging vessel 38 in separating bitumen from the remaining solidsand water (i.e. sludge). Diluted bitumen (i.e. naphtha plus bitumen)exits bitumen separator 38 via line 64 and is introduced into thenaphtha recovery system 62 where bitumen is separated from the naphtha.Bitumen leaves naphtha recovery system 62 via line 68 for upgrading(e.g. fluid coking, fractionating, hydrotreating, etc.). Recoverednaphtha is recycled back to the bitumen separator 38 to dilute theprimary and secondary bitumen froth. The sludge (i.e. remaining solidsand water) is removed from the bitumen separator 38 through line 70which introduces the sludge into line 35 that-conducts the tailingslayer from line 34 and the bitumen-lean water and sand tailings streamfrom line 56.

The tailings layer emanating through line 34, the bitumen-lean water andsand tailings stream emanating through line 56, and the sludge that isintroduced into line 35 from line 70, all make up a tailing dischargestream, which can be collected and handled via a dike building oroverboarding operation previously described. The tailing dischargestream is continuous and uniformly delivers into the retention pond 24.

The retention pond 24 can be considered another separation zone; it is azone of quietness. Both the dike building and overboarding operationresult in what is commonly referred to as a pond, particularly aretention pond. And as previously described, three layers are formed inthe pond. They are (1) a top water layer relatively free of clay andbitumen and which can be recycled; (2) a middle layer consisting ofbitumen and mineral (defined as not being soluble in toluene); and (3) abottom layer having a relatively high concentration of sand. The middlelayer is often referred to as sludge.

The sludge is continuously being formed in a time span of many monthsand even years. As a result, its characteristics are different thanthose of the middlings layer drawn off from the thickener vessel 28 vialine 40.

Referring in detail now to FIG. 2 there is seen sludge recovered fromretention pond 24 and being pumped by pump 100. Sludge has beenpreviously defined, but may also be defined as comprising 5 to 40 wt. %solids, 1 to 10 wt. % bitumen, and 50 to 95 wt. % water or aqueousmedium. Water or an aqueous phase is added to the sludge to dilute thesame and form a water/sludge mixture or slurry. The ratio of dilutionmay be any suitable ratio but is preferably a weight or part ratio ofwater to sludge ranging from about 1:1 to about 5:1. Preferably, aflotation or chemical additive is admixed with the water/sludge slurryin a proportion such that the ratio of the parts or weight of theflotation additive to undiluted sludge ranges from about 50 to about1,000 ppm. Stated alternatively, the flotation or additive is added tothe diluted sludge at a rate of 50 to 1,000 ppm based on undilutedsludge. Preferably further, air is injected into the water/sludge slurryat a ratio varying from about 0.02 to about 0.20 lbs. air/lb. bitumen inthe sludge.

The flotation or chemical additive may be selected from the groupconsisting of kerosene, diesel, methyl isobutyl carbinol (MIBC),petroleum sulfonate (e.g. that sold under the trademark WITCO PetronateHL), C₆ to C₉ branched aliphatic alcohols and/or ketones (such as thatsold under the trademark Sherex Shurcoal-177), at least one ethoxylatedalkylphenol compound, at least one ethoxylated dialkylphenol compound,and mixtures thereof.

The at least one ethoxylated alkylphenol compound is an emulsifyingagent(s) (or flotation or chemical additive) selected from theethoxylated alkylphenol compounds having a molecular weight distributionwith a dispersity of from about 1.0 to about 5.0, a weight averagemolecular weight of from about 1966 to about 9188, and the generalformula: ##STR1## wherein n₁ is an integer and has a value of from about7 to about 20, preferably11, and u₁ is an integer having a value of fromabout 4 to about 1000; and wherein at least about 50% by weight of theemulsifying agent(s) comprises the ethoxylated alkylphenol compoundhaving a molecular weight of from about 1966 to about 9188. Theemulsifying agent(s) has at least one ethoxylated alkylphenol compoundhaving the general formula: ##STR2## wherein n₁ has a value of fromabout 7 to about 20, preferably 11; and y₁ is greater than 100,preferably greater than 100 but less than 1000, and the ethoxylatedalkylphenol compound of general formula (1A) preferably comprises atleast 1% by weight (more preferably from 1% to 90% by weight) of theemulsifying agent(s) or flotation/chemcial additive.

More preferably, the dispersity of the molecular weight distribution ofthe emulsifying agent(s) represented by general formula (1) is fromabout 1.0 to about 2.5, most preferably about 1.0 to 2.0. The weightaverage molecular weight of the emulsifying agent(s) is more preferablyfrom about 3726 to about 6548, most preferably from about 4606 to 5668.More preferably, at least about 70% by weight (most preferably, at leastabout 85% by weight) of the-emulsifying agent(s) comprises theethoxylated alkylphenol compound having a molecular weight of from about1966 to about 9188.

The at least one ethoxylated dialkylphenol compound in the presentinvention may be those emulsifying agent(s) (or chemical or flotationadditive) selected from the ethoxylated dialkylphenol compounds having amolecular weight distribution with a dispersity of from about 1.0 toabout 5.0, a weight average molecular weight of from about 2519 to about11,627, and the general formula: ##STR3## wherein n₁ is an integer andhas a value of from about 7 to about 18, n₂ is an integer and has avalue of from about 7 to about 18, and y₂ is an integer having a valueof from about 4 to about 1000; and wherein at least about 50% by weightof the emulsifying agent (s) comprises the ethoxylated dialkylphenolcompound having a molecular weight of from about 2519 to about 11,627.The emulsifying agent(s) has at least one ethoxylated dialkylphenolcompound having the general formula: ##STR4## wherein n₁ has a value offrom about 7 to about 18, n₂ has a value of from about 7 to about 18,and y₂ is greater than 100, preferably greater than 100 but less than1000; and the ethoxylated dialkylphenol compound of general formula (2A)preferably comprises at least 1% by weight (more preferably from 1% to90% by weight) of the emulsifying agent(s) or flotation/chemicaladditive.

More preferably, the dispersity of the molecular weight distribution ofthe emulsifying agent(s) (or flotation or chemical additive) representedby the general formula (2) is from about 2.5, most preferably about 1.0to 2.0. The weight average molecular weight of the emulsifying agent(s)(or flotation or chemical additive) is more preferably from about 4714to about 8547, most preferably from about 6039 to about 7227. Morepreferably, at least about 70% by weight (most preferably, at leastabout 85% by weight) of the emulsifying agent(s) comprises theethoxylated dialkylphenol compound having a molecular weight of fromabout 2519 to about 11,627.

The flotation or chemical additive or emulsifying agent(s) may be acombination of the ethoxylated alkylphenol compounds having the generalformula (1) and the ethoxylated dialkylphenol compounds having thegeneral formula (2) in any percent by weight proportion provided thatthe dispersity of the molecular weight distribution of the entirecombination is from about 1.0 to about 5.0 (more preferably about 1.0 toabout 2.5 and most preferably about 1.0 to 2.0), and the weight averagemolecular weight in the combination of the emulsifying agent(s) [or ingeneral formula (1) and/or in general formula (2)] is about 1966 toabout 11,627 (more preferably about 3726 to about 8547, most preferablyabout 4606 to about 7227). Furthermore, the entire combination shouldcomprise at least 50% by weight (more preferably at least about 70% byweight, most preferably at least about 85% by weight) of the ethoxylatedalkylphenol compound and the ethoxylated dialkyphenol compound whereinthe ethoxylated alkylphenol compound has a molecular weight of fromabout 1966 to about 9188 and the ethoxylated dialkylphenol compound hasa molecular weight of from about 2519 to about 11,627. More preferably,the compounds having the general formula (1) are from about 30% byweight to about 80% by weight of the combination. Furthermore, at least1% by weight (preferably 1% to 90% by weight) of the combination of theethoxylated alkylphenol compound having the general formula (1) and theethoxylated dialkylphenol compound having the general formula (2)comprises the ethoxylated alkylphenol compound having the generalformula (1A) and/or the ethoxylated dialkylphenol compound having thegeneral formula (2A), where y₁ and y₂ are both greater than 100,preferably greater than 100 but less than 1000.

In a more preferred embodiment of the present invention the flotation orchemical additive comprises about 50 percent by weight of an ethoxylateddialkyphenol compound having the formula: ##STR5## and about 50 percentby weight of an ethoxylated alkylphenol compound having the formula:##STR6## wherein y₁ in both formulas is equal to 150 and is the averagenumber of ethylene oxide units in the formulas. In another morepreferred embodiment of the present invention the flotation or chemicaladditive comprises about 50 percent by weight of an ethoxylated nonylphenol compound having the formula: ##STR7## wherein y₁ is equal to 40and is the average number of ethylene oxide units in the formula, andabout 50 percent by weight of an ethoxylated nonyl phenol compoundhaving the formula: ##STR8## wherein y₂ is equal to 100 and is theaverage number of ethylene oxide units in the formulas.

The water/sludge/air mixture or slurry (or water/sludge/air/flotationadditive mixture or slurry) is pumped by pump 100 through a mixer 102,preferably one of the static mixers as disclosed in U.S. Pat. No.4,725,287 fully incorporated herein by reference thereto. Thewater/sludge/air mixture (or water/sludge/air/flotation additivemixture) is further agitated and/or mixed by passing through mixer 102since pump 100 and aeration in themselves are agitators and/or mixers.After passing through mixer 102 the mixture or slurry is introduced intoa settling zone (or flotation cell 104) or sludge pretreatment zone fora residence time which varies from about 10 minutes to about 2 hours toproduce an upper bitumen-containing froth layer comprising recoveredbitumen recovered from the sludge, and a lower sludge layer reduced inbitumen content.

The recovered bitumen in the upper bitumen-containing froth layerrepresents 20 to 40 wt. % of the bitumen in the original sludge. Thelower sludge layer reduced in bitumen content is essentially theoriginal sludge after having been reduced by 20 to 40 wt. % of itsbitumen. The upper bitumen-containing froth layer leaves flotation cell104 through line 106, and the lower sludge layer leaves flotation cell104 through line 108 and is pumped by pump 110 towards mixer 112. Beforereaching mixer 112 an oxidant is added to the lower sludge layer in anamount, quantity or proportion such that the ratio of the parts orweight of the oxidant to the lower sludge layer (or pretreated sludge)ranges from about 100 to about 20,000 ppm, preferably 1,000 ppm to 5,000ppm. Stated alternatively, the oxidant addition ranges from about 100 toabout 20,000 ppm based on the pretreated sludge. Before reaching mixer112 the lower sludge layer is aerated with air in a ratio or proportionranging from about 0.02 to about 0.2 lbs. air per lb. of bitumen in thelower sludge layer.

The oxidant is selected from the group consisting of sodium hypochlorite(NaClO), sodium chlorite (NaClO₂), sodium chlorate (NaClO₃), potassiumpermanganate (KMnO₄), ozone (O₃), chlorine (Cl₂), chlorine (Cl₂) andwater (H₂ O), hydrogen peroxide (H₂ O₂), and mixtures of any of theforegoing. Preferably, the oxidant is hydrogen peroxide.

After passing through mixer 112, the agitated slurry or mixture entersinto a settling zone (or flotation cell 114) or sludge treatment zonefor a residence time varying from about 10 minutes to about 2 hours toproduce an upper bitumen-containing froth layer comprising furtherrecovered bitumen, further recovered from the pretreated or lower sludgelayer from cell 104, and a lower sludge layer reduced in bitumencontent. The further recovered bitumen in the upper bitumen-containingfroth layer represents 30 to 70 wt. % of the bitumen in the pretreatedsludge or the lower sludge layer leaving flotation cell 104 through line108. The lower sludge layer produced in cell 114 and reduced in bitumencontent is essentially the pretreated sludge (or lower sludge layer inline 108) after having been reduced 30 to 70 wt. % of its bitumen. Theupper bitumen-containing froth layer leaves flotation cell 114 throughline 116 and may be admixed with the upper bitumen containing frothlayer in line 106. The lower sludge layer leaves flotation cell 114through line 118 and is pumped by pump 120 towards mixer 122. Beforereaching mixer 122 a flocculent (e.g. FeCl₃) is added to the lowersludge layer leaving cell 114 in line 118. The flocculent is added tothe lower sludge layer (or treated sludge) in an amount, quantity orproportion such that the ratio of the parts or weight of the oxidant tothe lower sludge layer (or treated sludge) ranges from about 500 toabout 25,000 ppm. Stated alternatively, the flocculent addition rangesfrom about 500 to about 25,000 ppm based on the treated sludge.

After passing through mixer 122, the agitated slurry or mixture entersinto a separator or clarifier 124 for a residence time varying fromabout 30 minutes to about 24 hours to produce clarified water (whichexits the clarifier 124 through line 126) and a tail or solidconcentrate containing water and exiting the clarifier 124 through line128. The clarified water in line 126 represents 10 to 50 wt. % of thewater in the lower sludge (or treated sludge)/flocculent mixture orslurry. The tail or solid concentrate containing water comprises 15 to60 wt. % of the solids in the lower sludge (or treatedsludge)/flocculent mixture or slurry, and is introduced into afilter/centrifuge 130 to produce additional clarified water that exitsthe filter/centrifuge 130 via line 134 for admixing with water in line126 for recycling to be mixed with the sludge from retention pond 24, orfor disposal. The filter/centrifuge 130 also produces solids containing1 to 5 wt. % water and exiting the filter/centrifuge 130 via line 132for disposal or other use.

Thus, there is provided a method for recovering bitumen in or fromsludge and to dispose of tailings pond water and clays/solids sand in anenvironmentally acceptable manner. The process or method of the presentinvention is applicable to treating effluent tailings from commercialextraction plants. The recovered water can be used as recycle tominimize fresh water make-up. A secondary purpose is to eliminate theenvironmentally unacceptable tailings ponds.

Current technology practiced at Syncrude and Suncor in Alberta, Canadaproduces large quantities of sludge. Typical analysis of Suncor sludgeand particle size distribution of clays-sand are as follows:

    ______________________________________                                        Suncor Tailings Pond                                                                         Sludge Pond #1                                                                            Sludge Pond #2                                     ______________________________________                                        % H.sub.2 O    54.9        62.7                                               % Bitumen      5.6         7.6                                                % Solids       39.4        29.7                                               % < 22 microns 76.7        64.5                                               % < 11 microns 57          44.7                                               ______________________________________                                    

The sludge from Pond 1 has physical characteristics which are similar tomayonnaise in consistency. Treating the sludge with known agents such asHCl to finalize a pH of 1.5 to 2 had little beneficial effect onphysical properties.

The disadvantages of the current commercial processes are two fold, i.e.loss of bitumen and production of tailings contributing to an everincreasing tailings pond which cannot be abandoned. There are no knowncommercial processes which recover the bitumen and dispose of the liquidand solids in an acceptable manner.

The two stage process utilizes an oxidizing agent in the 1st stage whichhas proven to be effective in conditioning the sludge, i.e. in breakingthe stable colloidal suspension by reacting with a sludge component, andfloating the bitumen (formerly complexed with clays) to the surface.Hydrogen peroxide (applied at a rate of approximately 1% of sludgevolume) was found to be effective in recovering bitumen from sludgesamples of Suncor's Sludge Pond #1 while simultaneously producing aclean clay-sand reject. The second stage of the process includes theaddition of a flocculent such as FeCl₃ which produces a clear liquid andessentially dry solids for disposal using conventional technology.

In another embodiment of the present invention, there is provided aprocess for recovering a hydrocarbon from a hydrocarbon bearing sand.More specifically there is provided a process for recovering bitumenfrom tar sands. As previously mentioned, the following U. S. Patentsteach an apparatus and/or method for removing a hydrocarbon or the likefrom hydrocarbon bearing particulate matter or the like: U.S. Pat. Nos.3,068,167 to White; 3,297,568 to McMahon; 3,392,105 to Poettmann et al;3,696,923 to Miller; 3,864,251 to Cymbalisty; 3,869,384 to Schutte;4,018,664 to Bain et al; 4,229,281 to Alquist et al; 4,340,487 to Lyon;4,368,111 to Siefkin et al; 4,392,941 to Roth et al; 4,514,305 to Filby;4,891,131 to Sadeghi et al; 4,913,805 to Chin; 4,946,597 to Sury;4,968,412 to Guymon; 5,009,773 to Schramm et al; 5,019,245 to Ignasiaket al; 4,036,732 to Irani et al; 4,071,434 to Gifford; 4,110,194 toPeterson et al; 4,347,118 to Funk et al; 4,383,914 to Kizior; 4,399,039to Yong; 4,424,112 to Rendall; 4,676,889 to Hsieh et al; 4,702,487 toStoian et al; 4,719,008 to Sparks et al; 4,776,949 to Leung et al; and4,929,341 to Thirumalachar et al. All of these U.S. Patents will befully incorporated herein by reference thereto as if fully repeatedverbatim immediately hereafter.

In this other preferred embodiment of the present invention, ahydrocarbon bearing sand, preferably an Athabasca tar sand from theAthabasca deposit at Fort McMurray, Alberta, Canada, is mixed with orotherwise co-mingled with an aqueous medium or phase, agitated to form aslurry, and then introduced directly into an enhanced gravity separator.Athabasca tar sands are water wet tar sands, as opposed to oil wet tarsands as taught in U.S. Pat. No. 4,368,111 to Siefkin et al, andtypically have a pH of between about 6.0 and about 7.0 (or less than7.0). The aqueous medium or phase and tar sand mixture or slurrypreferably has a temperature between about 75° F. and 200° F. Theagitated Athabasca tar sand and water mixture or slurry is introduceddirectly into an enhanced separator without being admixed with any pHcontrolling agents, such as NaOH. Stated alternatively, no causticagents are to be added to raise the pH of the slurry from 7.0 to 8.5. Ina conventional "hot water" extraction process, NaOH is added to theslurry to elevate the pH, and the sodium ion from NaOH in combinationwith other tar sands constituents causes the formation of sludge. Theagitated Athabasca tar sand and water slurry is introduced directly intoan enhanced separator without passing into any separator such as athickener vessel and/or flotation vessel, or into any other container orvessel for any suitable purpose.

The enhanced gravity separator of the present invention is one in whichthe feed (i.e., the tar sand slurry) is subjected to definedgravitational forces tending to separate the heavier sand from thelighter fluids (e.g., water and bitumen) in less than about 5 seconds,preferably less than about 2 seconds. The most preferred enhancedgravitational separator is a hydrocyclone type of separator that has an"involuted" feed entrance, as opposed to a straight tangential typeentrance (see FIG. 3), with a rectangular opening having itslongitudinal length-wise dimension (i.e., the greater dimension)parallel to the axis of the cyclone. It is thought that an "involuted"feed entrance introduces the tar sand slurry with much less turbulencethan a straight tangential type entrance. A preferred hydrocyclone isthat sold by Krebs Engineers of Menlo Park, California. As shown in FIG.4, the configuration of the hydrocyclone sold by Krebs Engineersintroduces the tar sand slurry into the hydrocyclone along the innerwall, forcing the mixture to rotate at a high angular velocity. Thekinetic energy of the tar sand feed stream is in this manner convertedto centrifugal force. Essentially all of the solids are separated fromthe bitumen/hydrocarbon and water in less than about 5 seconds,typically less than about 2 seconds. Coarser and heavier solids areconcentrated and discharged through the apex orifice as underflow. Mostof the tar sand feed liquid (i.e., water plus bitumen) and a part of thevery fine solids (i.e., fines) discharge through the vortex finder asoverflow. The overflow (water plus bitumen plus fines) may be sent to abitumen water separator to remove the bitumen which in turn may be sentdirectly to an upgrading or conversion unit with or without removal of aportion of the water or the solids. The removed fines plus water may besent to one or more separators to remove the fines and recover water tobe heated and recycled for admixing with Athabasca tar sands to producemore tar sand slurry. An alternative is to leave some of the fines andwater with the bitumen to be processed in a special upgrading orconversion process, which utilizes a portion of the water and naturallyoccurring clays.

Preferably one or more chemical additive(s) or chemical agents(s) is orare added to the Athabasca tar sand/water mixture or slurry eitherbefore or during mixing and/or agitation. The chemical additive(s) orchemical agent(s) may be kerosene, diesel, kerosene/diesel, MIBC(methyl-isobutyl-carbinol), calcium lignosulfonate (i.e. sold under thetrademark Lignosite Road Binder 50% by Georgia Pacific), Petronate HL(i.e. petroleum sulfonate sold under the trademark WITCO Petronate HL),SC-177 (i.e. a C₆ to C₉ branched aliphatic alcohols and/or ketones soldunder the trademark Sherex Shurcoal 177); DP-DNP-150; NP40/NP100; ormixtures of any of the foregoing. The chemical agent(s) is preferablykerosene and/or diesel in combination with DP and DNP, more preferablykerosene and/or diesel in combination with a 50/50 mixture of DP and DNPwith each having 150 ethoxylated groups; or kerosene and/or diesel incombination with NP40 and NP100, preferably kerosene and/or diesel incombination with a 50/50 mixture of NP40 and NP100. The one or morechemical additive(s) may be added in any suitable quantity orproportions, but is preferably added in an amount or quantity rangingfrom about 25 to about 2500 parts of chemical additive(s) perone-million (1,000,000) parts of tar sands (i.e., sand plus bitumen plusconnate water, etc); more preferably from about 50 ppm to about 1200ppm; and most preferably from about 50 ppm to about 150 ppm.

Preferably after the tar sand slurry has been prepared, or after the tarsand slurry plus chemical additive(s) have been mixed together, theresulting liquid slurry is subjected to aeration before being introducedinto the enhanced gravity separator (i.e., the hydrocyclone). Aerationmay be at any suitable rate but preferably ranges from about 0.1 SCF ofair per gallon of liquid slurry to about 1.0 SCF of air per gallon ofliquid slurry; most preferably from about 0.2 SCF/gallon to about 0.5SCF/gallon.

Preferably after the tar sand slurry has been aerated, or after the tarsand slurry plus chemical additive(s) have been aerated, the resultingaerated slurry is passed through one or more agitator(s) before beingintroduced into the enhanced gravity separator. The agitator(s) may beany suitable agitator (e.g., dynamic, static, etc.) but is preferably onone or more of the static mixers, such as any of those disclosed inco-pending application Ser. No. 341,772, filed Apr. 21, 1989, fullyincorporated herein by reference thereto as if repeated verbatimhereafter.

Referring in detail now to FIG. 5 for another discussion of the presentembodiment and best mode of the invention, there is seen a slurrypreparation chamber 200 (e.g., a tumbler, mixer, etc.) having lines 202,204 and 206 leading thereto. Athabasca tar sands pass through line 202and into the slurry preparation chamber 200. As previously mentioned,Athabasca tar sands are water wet tar sands having a pH of from 6.0 toless than about 7.0, more likely around 6.5. An aqueous phase (i.e.,water) passes through line 204 and into the slurry preparation chamber200. The water may be make-up water from any suitable source, such as aretention pond, and/or recycled water. The water is preferably heatedfirst by heater 208 such that when the heated water is admixed with theAthabasca tar sands, or with the Athabasca tar sands and any one or morechemical additive(s) that pass through line 206 and into the slurrypreparation chamber 200, the resulting tar sand slurry has a temperatureof from about 75° F. to about 200° F., more preferably from about 100°F. to about 130° F.

The one or more chemical additive(s) or agent(s) may be any chemicalthat is capable of assisting the removal of bitumen from sand,especially when admixed with hot water and agitated. Preferably, thechemical additive or agent is one or more of the following chemicals:kerosene, diesel, MIBC, Petronate HL, SC-177, and calcium lignosulfate,NP40/NP100, DP-150/DNP-150, and mixtures thereof. Preferably thechemical agent comprises at least one ethoxylated alkylphenol compoundhaving the general formula: ##STR9## wherein n₁ is an integer having avalue of from about 7 to about 20, and Y₁ is an integer having a valueof from about 4 to about 1000; and said at least one ethoxylatedalkylphenol compound has a molecular weight distribution with adispersity of from about 1.0 to about 5.0 and with a weight averagemolecular weight of from about 1966 to about 9188; and wherein at leastabout 50% by weight of the chemical agent comprises said at least oneethoxylated alkylphenol compound having a molecular weight of from about1966 to about 9188. From 1% by weight to about 90% by weight of thechemical agent comprises the at least one ethoxylated alkylphenolwherein Y₁ has a value greater than 100. Preferably, the chemical agentcomprises from about 30% by weight to about 80% by weight of the atleast one ethoxylated alkylphenol compound; and/or the chemical agentadditionally comprises at least one ethoxylated dialkylphenol compoundhaving the general formula: ##STR10## wherein n₂ is an integer having avalue of from about 7 to about 18, and n₃ is an integer having a valueof from about 7 to about 18, and y₂ is an integer having a value of fromabout 4 to about 1000; and wherein said at least one ethoxylateddialkylphenol compound and said at least one ethoxylated alkylphenolcompound have a molecular weight distribution with a dispersity of fromabout 1.0 to about 5.0 and with a weight average molecular weight offrom about 1966 to about 11,627; and wherein at least about 50% byweight of the chemical agent comprises said at least one ethoxylatedalkylphenol compound having at least one ethoxylated dialkylphenolcompound having a molecular weight of from about 2519 to about 11,627;and from 1% by weight to 90% by weight of the chemical agent comprisessaid at least one ethoxylated dialkylphenol compound wherein y₂ isgreater than 100. Stated alternatively, the chemical additive or agentmay be those chemicals or compounds represented by general formula (1)and/or general formula (1A) and/or general formula (2) and/or generalformula (2A), all as previously defined above as a flotation additivefor the water/sludge slurry (as depicted in FIG. 2) including having atleast 1% by weight with y₁ and y₂ greater than 100. Stated alternativelyfurther, the chemical additive may be a 50/50 mixture of NP-40/NP-100 orDP-150/DNP-150 as stated and defined above.

The conditioned and prepared tar sand slurry leaves the slurrypreparation chamber 200 via line 210 and is pumped by pump 212, which ispreferably a centrifugal pump causing agitation of the tar sand slurry,at a rate of 10 to 30 gallons per minute towards one or morehydrocyclones 216 (i.e., primary separator). As the tar sand slurry isbeing pumped through line 210, air is introduced into line 210 via line214 at a rate of from about 1 to about 20 SCF/minute. After aeration,the aerated tar sand slurry passes through one or more static mixers (oragitators) 215 for further agitation and then into one or more involutedfeed hydrocyclones 216 where bitumen and water and fines are removedthrough the vortex finder and separated from the coarser solids, whichare discharged through the apex orifice of each hydrocyclone 216 asunderflow. The aerated tar sand slurry, in addition to being agitated bypump 212 and static mixer 215, may be further agitated by extending thelength of line 210, say to 100 feet or greater.

The bitumen, water and fines mixture is sent from the vortex finder ofeach hydrocyclone 216 through line 226 and into a bitumen/waterseparator 228 where bitumen is separated from the water and fines.Bitumen leaves the separator 228 via line 230 to an upgrading unit 232where the bitumen is upgraded into one or more lighter products. Theupgrading unit by way of example only includes coking (both fluid anddelayed), hydrovisbreaking, thermal visbreaking, and hydrocracking. Someof the water and fines (clays) may be retained in the bitumen forprocessing in a special upgrading unit which utilizes carbonmonoxide toassist in the bitumen conversion.

Water and fines leave the separator 228 through line 234 and are pumpedby pump 236 towards one or more hydrocyclones 238 where water is removedthrough the vortex finder of each hydrocyclone 238 from the fines thatpass out of each hydrocyclone 238 into line 240 where they are sent todisposal. Water passes into line 204 where pump 244 pumps the water asrecycle water through heater 208 for heating and subsequently to theslurry preparation chamber 200. Make-up water (from a retention pond,etc.) may be added to the recycle water.

As the coarser solids pass through the apex orifice of each hydrocyclone216 and into line 217, water may be added or admixed therewith and theresulting mixture is then sent to one or more hydrocyclones 218 forremoval of any entrained residual bitumen in the coarser solids. Morespecifically, water and coarser solids (including entrained bitumen) issent to one or more hydrocyclones 218 where residual bitumen and water(and possibly residual fines) are removed through the vortex finder ofeach hydrocyclone 218 and pass into line 219. Line 219 hooks into line221 to pass residual bitumen and water (and possibly residual fines)from line 219 into line 221. Line 221 leads into line 226, which aspreviously mentioned conducts bitumen, water and fines to the separator228. The coarser solids, absent essentially all fines and residualbitumen and water, leave the hydrocyclone(s) 218 through line 220 wherepump 222 pumps the coarser solids to disposal.

The invention will be illustrated by the following set forth exampleswhich are given by way of illustration and not by any limitation. Allparameters such as concentrations, mixing proportions, temperatures,pressure, rates, compounds, etc., submitted in these examples are not tobe construed to unduly limit the scope of the invention.

EXAMPLE I

FIGS. 6,7,8 and 9 depict Process Option 1, Process Option 2, ProcessOption 3, and Process Option 4, respectively, for operation of thepresent invention. Process Option 1 is slurry preparation followed byprimary and secondary separation and recycle of bottoms from the bitumenconcentrates step to slurry preparation. Process Option 2 is essentiallythe same as Option 1 with the elimination of the secondary separationand recycle step from Option 1. Process Option 3 includes primary andsecondary separation with combination of the bottoms from bitumenconcentration with the bitumen concentrate product, rather than recycleof this stream to slurry preparation. Process Option 4 is essentiallythe same as Option 3 with the exception that there is no secondaryseparation.

Common in all Process Options 1,2,3 and 4 are the following primarysteps:

Slurry Preparation: This step involves mixing of the raw tar sand withwater and chemicals of the present invention and heating to the desiredoperating temperature. Agitation is required to break up the sand matrixand free the bitumen. The role of the chemical additives is to aid inthe sand/bitumen separation and also to condition the bitumen dropletsfor air attachment. Screening of the slurry may also be included in thisstep to prevent passage of oversize material to downstream units.

Primary Separation: Following slurry preparation air is introduced intothe slurry and aerated slurry is pumped to the primary separation units(hydrocyclones) for separation of solids (i.e., sand) from the liquids(i.e.,water and bitumen) in five (5) seconds or less. Residence time andmixing is required in the pipeline to the separators to provide time forair attachment. An alternative to direct air injection is injection ofpressurized water containing dissolved air which is released fromsolution in the slurry. In the primary hydrocyclones the bulk of thesand is rejected to a tailings stream while most of the water, bitumenand fines go overhead.

Bitumen Concentration: The overhead stream from the primary separatorscontains mostly water which is separated from the bitumen before thebitumen can be transported and processed. This unit may be anyconventional separators or settler such as an open vessel in which themajority of the bitumen rapidly floats to the surface and is skimmed offwith some water and solids. The heavier solids and some bitumen sinks tothe bottom and is recovered as a tails stream. A side stream iswithdrawn which contains most of the water, fines and some bitumen.Bitumen recovery from this vessel is accomplished within several hoursor less. The water-rich side stream may be sent elsewhere for furtherclarification which may occur in a vessel or pond with a residence timeof 24 hours or less.

Secondary Separation: The tails stream from the primary separatorscontains 10 to 20% of the feed bitumen and may be further processed torecover part of this potentially lost product. This unit consists ofhydrocyclones similar to the primary separators. The feed to this systemis diluted with water before it is treated.

Fines Removal: The water stream from the bitumen concentration step maybe recycled to slurry preparation for balance of the water systemHowever, this stream contains most of the fines from the tar sand feed.The fines may be removed by hydrocyclones or in settling ponds or tanks.The preferred method is the use of hydrocyclones which limits residencetime and reduces bitumen losses.

                                      TABLE I                                     __________________________________________________________________________    The following Table I represents the flow/rates (lbs/hr) for the streams      (i.e. stream 1,                                                               stream 2 . . . stream 14) in FIG. 6 (i.e. Process Option 1) including the     recovered bitumen concentrate                                                 (i.e. stream 4) and the recovered sand (i.e. streams 5, 7 and 6):                          FLOW RATES, LBS/HR                                                            1    2     3     4      5   6    7                                            Tar Sand                                                                           Tar Sand                                                                            FSU   Bitumen                                                                              Coarse                                                                            Fine FSU                                          Feed Slurry                                                                              Overhead                                                                            Concentrate                                                                          Solids                                                                            Solids                                                                             Tails                           __________________________________________________________________________    Tar Sand, (1,000 tons/day)                                                    Bitumen       8467                                                                               13009                                                                              11708 7950     390                                                                              127 1301                            Solids > 44 microns                                                                        67189                                                                               69873                                                                               2096 1445    65743                                                                              0  67777                           Solids < 44 microns                                                                         4061                                                                               17070                                                                              15021 2019     246                                                                             1797 2048                            Water         3617                                                                              233220                                                                              164696                                                                              4892    65599                                                                            5263 68524                           Total        83333                                                                              333171                                                                              193521                                                                              16305  131978                                                                            7186 139650                          __________________________________________________________________________                 8    9     10    11     12  13   14                                           Dilution                                                                           Secondary                                                                           Secondary                                                                           Concentrato                                                                          Water/                                                                            Recycle                                                                            Make-up                                      Water                                                                              Feed  Overhead                                                                            Tails  Fines                                                                             Water                                                                              Water                           __________________________________________________________________________    Bitumen            1301   911 4246     423                                                                              296                                 Solids > 44 microns                                                                              67777                                                                               2033 2684      0                                                                                0                                  Solids < 44 microns                                                                              2048  1803 12691   2114                                                                              317                                 Water        65718                                                                              134242                                                                              68643 19622  208825                                                                            203562                                                                             6419                            Total        65718                                                                              205368                                                                              73389 39243  211362                                                                            204175                                                                             6419                            __________________________________________________________________________

                                      TABLE II                                    __________________________________________________________________________    The following Table II represents the flow/rates (lbs/hr) for the streams     (i.e. stream 1,                                                               stream 2 . . . stream 14) in FIG. 7 (i.e. Process Option 2) including the     recovered bitumen                                                             concentrate (i.e. stream 4) and the recovered sand (i.e. streams 5 and        6):                                                                                        FLOW RATES, LBS/HR                                                            1      2    3     4      5    6                                               Tar Sand                                                                             Tar Sand                                                                           FSU   Bitumen                                                                              Coarse                                                                             Fine                                            Feed   Slurry                                                                             Overhead                                                                            Concentrate                                                                          Solids                                                                             Solids                             __________________________________________________________________________    Tar Sand, (1,000 tons/day)                                                    Bitumen      8467    12286                                                                              11058                                                                              6966    1229                                                                               272                               Solids > 44 microns                                                                        67189   68525                                                                              2056  720   66469                                                                                0                                Solids < 44 microns                                                                        4061    12885                                                                              11339                                                                              1361    1546                                                                              1154                               Water        3617   218625                                                                             151838                                                                              3877   66787                                                                              3192                               Total        83333  312321                                                                             176290                                                                              12924  136031                                                                             4618                               __________________________________________________________________________                             11      12  13   14                                                           Concentrato                                                                           Water/                                                                            Recycle                                                                            Make-up                                                      Tails   Fines                                                                             Water                                                                              Water                               __________________________________________________________________________                Bitumen      3820      272                                                                                0                                                 Solids > 44 microns                                                                        1336       0                                                                                 0                                                 Solids <  44 microns                                                                       8620     1358                                                                               204                                                Water        13776   134185                                                                            130993                                                                             70239                                           Total        27552   135815                                                                            131197                                                                             70239                               __________________________________________________________________________

                                      TABLE III                                   __________________________________________________________________________    The following Table III represents the flow/rates (lbs/hr) for the            streams (i.e. stream 1,                                                       stream 2 . . . stream 15) in FIG. 8 (i.e. Process Option 3) including the     recovered bitumen concentrate                                                 (i.e. stream 4) and the recovered sand (i.e. streams 5, 7 and 6):                           FLOW RATES, LBS/HR                                                            1      2      3      4     5     6    7                                       Tar Sand                                                                             Tar Sand                                                                             FSU    Bitumen                                                                             Coarse                                                                              Fine FSU                                     Feed   Slurry Overhead                                                                             Froth Solids                                                                              Solids                                                                             Tails                     __________________________________________________________________________    Tar Sand, (1,000 tons/day)                                                    Bitumen        8467   8715  7844   5326    261  107  872                      Solids > 44 microns                                                                         67189   67189 2016   1390   63218                                                                                0  65173                     Solids < 44 microns                                                                          4061   4328  3808    512    62  1511  519                      Water          3617  187208 122387 3098   63019                                                                              4425 64821                     Total         83333  267440 136055 10325 126560                                                                              6043 131385                    __________________________________________________________________________                 8    9     10    11     12  13   14   15                                      Dilution                                                                           Secondary                                                                           Secondary                                                                           Concentrato                                                                          Water/                                                                            Recycle                                                                            Make-up                                                                            Bitumen                                 Water                                                                              Feed  Overhead                                                                            Tails  Fines                                                                             Water                                                                              Water                                                                              Concentrate                __________________________________________________________________________    Tar Sand, (1,000 tons/day)                                                    Bitumen             872  610  2773     355                                                                              249      8099                       Solids > 44 microns                                                                              65173                                                                              1955  2581      0                                                                                0       3971                       Solids < 44 microns                                                                               519  457  1976    1777                                                                              267      2488                       Water        61828                                                                              126649                                                                              63630 7330   175590                                                                            171165                                                                             12427                                                                              10428                      Total        61828                                                                              193213                                                                              66653 14660  177723                                                                            171680                                                                             12427                                                                              24985                      __________________________________________________________________________

                                      TABLE IV                                    __________________________________________________________________________    The following Table IV represents the flow/rates (lbs/hr) for the streams     (i.e. stream 1,                                                               stream 2 . . . stream 15) in FIG. 9 (i.e. Process Option 4) including the     recovered bitumen                                                             concentrate (i.e. stream 4) and the recovered sand (i.e. streams 7 and        6):                                                                                        FLOW RATES, LBS/HR                                                            1    2    3     4    6   7                                                    Tar Sand                                                                           Tar Sand                                                                           FSU   Bitumen                                                                            Fine                                                                              Coarse                                               Feed Slurry                                                                             Overhead                                                                            Froth                                                                              Solids                                                                            Solids                                  __________________________________________________________________________    Tar Sand, (1,000 tons/day)                                                    Bitumen      8467  8627                                                                               7764 4892  69  863                                    Solids > 44 microns                                                                        67189                                                                               67189                                                                              2016  705   0 65173                                   Solids < 44 microns                                                                        4061  4233                                                                               3725  447  975                                                                               508                                    Water        3617 186781                                                                             121963                                                                              2590 2855                                                                              64818                                   Total        83333                                                                              266831                                                                             135468                                                                              8634 3899                                                                              131362                                  __________________________________________________________________________              11     12   13    14    15                                                    Bit. Conc.                                                                           Water/                                                                             Recycle                                                                             Make-up                                                                             Bitumen                                               Tails  Fines                                                                              Water Water Concentrate                                 __________________________________________________________________________    Bitumen   2644     229                                                                                161       7535                                        Solids > 44 microns                                                                     1310      0     0       2016                                        Solids < 44 microns                                                                     2132    1147                                                                                172       2579                                        Water     6085   113287                                                                             110432                                                                              72732 8676                                        Total     12171  114663                                                                             110765                                                                              72732 20805                                       __________________________________________________________________________

                  TABLE V                                                         ______________________________________                                        SUMMARY OF FSU PROCESS OPTIONS                                                             Option Option  Option   Option                                                1      2       3        4                                        ______________________________________                                        Bitumen Retention, wt %                                                                      93.9     82.3    95.7   89.0                                   Sand Rejection, wt %                                                                         95.1     97.1    90.9   93.6                                   Bitumen Concentrate                                                           Composition                                                                   Bitumen, wt %  48.8     53.9    32.4   36.2                                   Sand, wt %     8.9      5.6     15.9   9.7                                    Fines, wt %    12.4     10.5    10.0   12.4                                   Water, wt %    30.0     30.0    41.7   41.7                                   Bitumen, vol % 55.1     59.0    37.9   41.2                                   Sand, vol %    4.0      2.4     7.4    4.4                                    Fines, vol %   7.0      5.8     5.8    7.0                                    Water, vol %   33.9     32.8    48.8   47.4                                   Total Flow, lb/hr:                                                            to Primary Sep.                                                                              333171   312321  267440 266831                                 to Secondary Sep.                                                                            205368      0    193213    0                                   to Bit. Conc.  266910   176290   76978 135468                                 to Fines Removal                                                                             211362   135815  177723 114663                                 Bitumen Concentrate                                                                           16305    12924   24985  20805                                 ______________________________________                                    

EXAMPLE II Bench Scale Laboratory Testing

The bench scale test program for evaluation of potential bitumenseparation additives (i.e. the chemical additives) and processingconditions and results are presented below. Promising additivecombinations have been identified and were evaluated in the pilothydrocyclone. The results of the tests indicate the sand reductionconcept of this invention is feasible.

SUMMARY

Potential chemical additives for enhancement of bitumen separation fromtar sands were selected for use in the pilot tests of the hydrocycloneseparator. A bench scale experimental program was used to screencombinations of commercial and experimental chemical additives. Theapparatus and procedures used were based on modifications of publishedmethods used by Syncrude Ltd. for bench scale evaluation of the hotwater-caustic wash process. Forty-two runs were completed in which 500 gof tar sand were slurried with water and additives and subjected to acontrolled mixing and separation procedure. Product was collected fromthe separation vessel at set times throughout the test and analyzed forbitumen, solids and water content. The effectiveness of each additivecomposition was evaluated based on the rate of bitumen separation, thetotal bitumen recovered, the rejection of sand from the product, and thequality of the water recovered from the separation vessel.

Five chemical agents including methyl isobutyl carbinol (MIBC),Petronate HL, Sherex Shurcoal 177, CS104 (a 50/50 mixture of NP-40 andNP-100), and DP-DNP-150 (a 50/50 mixture DP-150 and DNP-150) incombination with kerosene and/or diesel are recommended. Use of theseadditives significantly enhanced the rate of bitumen recovery, the totalbitumen recovered and the rejection of sand from the recovered product.The additives were effective at temperatures as low as 100° F. (38° C.)and at treatment rates from 100 to 600 ppm based on total tar sand feed.

The most effective combination of additives was found to be DP-DNP-150(a 50/50 mixture of ethoxylated dodecyl phenol and dinonyl phenol with150 EO groups) at 300 ppm based on total tar sand feed and kerosene at600 ppm based on total tar sand feed. Use of this additive package at100° F. yielded a total recovery of 92.8% of the bitumen feed, rejectionof 85% of the sand and clay, a bitumen separation rate of 14.7%/min(based on total bitumen feed), and an acceptable water quality forrecycle. At a DP-DNP-150 treatment rate of 100 ppm based on slightreduction in performance was observed. Tests at a lower temperature (80°F.) resulted in poor separation.

EXPERIMENTAL PROCEDURES AND MATERIALS

The experimental and analytical procedures for evaluation of thechemical additives were modified and improved as the tests progressedand experience in operation of the system was gained.

The additives used in the screening tests were selected fromcommercially available materials which are used in coal cleaningoperations and from surfactants which have been previously used inoperations relating to emulsification of bitumen. The additives used arelisted in Table VI. below.

                  TABLE VI                                                        ______________________________________                                        Additives Tested in Screening Tests                                           ______________________________________                                        1.  MIBC -      Methyl Isobutyl Carbinol                                      2.  SC177 -     Sherex Shurcoal 177 (Alcohols & Ketones)                      3.  SC164a -    Sherex Shurcoal 164a (Alcohols & Ketones)                     4.  DPM -       Dipropylene glycol monomethyl ether                           5.  PetHL -     Petronate HL (Sodium petroleum                                                sulfonate)                                                    6.  PetL -      Petronate L HL (Sodium petroleum                              7.  Cresol -    sulfonate)                                                    8.  NP12 -      Ethoxylated nonyl phenol with 12 EO's                         9.  NP20 -      Ethoxylated nonyl phenol with 20 EO's                         10. CS104 or    NP-40 + NP100                                                     CS 83                                                                     11. NP100-150 - Mixture of ethoxylated nonyl phenols with                                     100 and 150 EO's                                              12. TDA-150 -   Ethoxylated tridecyl alcohol with 150 EO's                    13. DP-DNP-150 -                                                                              Mixture of ethoxylated dodecyl phenol and                                     dinonyl phenol with 150 EO's.                                 ______________________________________                                    

TEST RESULTS

After a series of 16 preliminary tests during which experimentalprocedures were modified and refined, a test program was initiated inwhich established procedures were used for consistency betweenevaluations. Based on results of the preliminary test phase, a basecondition was established for comparison of the various additivecombinations. The base test conditions included the following:

    ______________________________________                                        Operating temperature   100° F.                                        Sample size             500 g.                                                Slurry water for conditioning                                                                         150 ml                                                Chemical 1              kerosene                                              Chemical 1 concentration                                                                              600 ppm                                               Chemical 2              MIBC                                                  Chemical 2 concentration                                                                              600 ppm                                               ______________________________________                                    

In addition to tests of various combinations of additives, the use ofcaustic at 180° F. was tested for comparison with the standard hotwater-caustic wash process.

The results of test runs 16 through 42 are summarized in the followingTable VII.

                                      TABLE VII                                   __________________________________________________________________________    Summary of Flotation Results - Additive Screening Tests                                             Init.                                                                             Recov.  Tail.                                                                            Bit.                 Water                                 Feed                                                                              Rate                                                                              @ 20                                                                              Total                                                                             Bit.                                                                             Mat.                                                                              Product Composition                                                                        Sand                                                                              Qual                Run                                                                              Additive 1/                                                                         Additive                                                                           Temp.                                                                             Conc.                                                                             %/min                                                                             Min Recov.                                                                            %  Bal. %                                                                            Bitumen                                                                            Water                                                                             Solids                                                                            Reject.                                                                           @ 24 Hr             No.                                                                              ppm   2/ppm                                                                              F.  % (1)                                                                             (2) % (3)                                                                             % (4)                                                                             (5)                                                                              (6) wt. %                                                                              wt. %                                                                             wt. %                                                                             %                                                                                 (8)                 __________________________________________________________________________    16 MBC/600                                                                             Kero/600                                                                           100 10.4                                                                              2.3 77.5                                                                              93.6                                                                              0.67                                                                             99.0                                                                              30.3 27.2                                                                              42.3                                                                              84.3                                                                              3                   17 MBC/600                                                                             Kero/600                                                                           100 11.5                                                                              9.4 79.5                                                                              89.7                                                                              1.14                                                                             99.0                                                                              32.2 27.0                                                                              40.8                                                                              84.7                                                                              4                   18 SC177/600                                                                           Kero/600                                                                           100  9.9                                                                              11.1                                                                              82.3                                                                              92.0                                                                              0.57                                                                             99.0                                                                              21.4 22.3                                                                              56.3                                                                              72.5                                                                              5                   19 MBC-NP12                                                                            Kero/600                                                                           100 10.4                                                                              10.3                                                                              79.9                                                                              90.3                                                                              0.96                                                                             99.0                                                                              23.2 27.7                                                                              49.1                                                                              76.9                                                                              7                   20 MBC/600                                                                             Dies./600                                                                          100 11.1                                                                              14.5                                                                              86.0                                                                              91.6                                                                              0.68                                                                             99.0                                                                              34.2 24.2                                                                              41.6                                                                              85.6                                                                              6                   21 DPM/600                                                                             Kero/600                                                                           100 10.7                                                                              8.2 72.1                                                                              89.3                                                                              1.03                                                                             99.0                                                                              26.0 22.0                                                                              52.1                                                                              77.7                                                                              6                   22 Kero/600   100 10.1                                                                              9.0 72.8                                                                              88.9                                                                              1.00                                                                             99.0                                                                              23.7 26.4                                                                              49.9                                                                              78.1                                                                              2                   23 CS104/600                                                                           Kero/600                                                                           100 10.6                                                                              10.9                                                                              89.0                                                                              93.3                                                                              0.38                                                                             99.0                                                                              29.2 21.0                                                                              49.8                                                                              80.6                                                                              2                   24 Diesel/600 100 10.9                                                                              7.8 73.3                                                                              86.8                                                                              1.43                                                                             99.0                                                                              24.5 28.5                                                                              47.0                                                                              79.0                                                                              4                   25 MBC/600                                                                             Dies./600                                                                          100 10.6                                                                              10.4                                                                              87.3                                                                              96.6                                                                              0.52                                                                             103.1                                                                             29.1 22.3                                                                              48.6                                                                              80.2                                                                              5                   26 NP20/600                                                                            Kero/600                                                                           100 10.6                                                                              3.6 47.1                                                                              92.5                                                                              1.10                                                                             101.9                                                                             30.8 33.2                                                                              35.9                                                                              86.7                                                                              7                   27 PetL/600                                                                            Kero/600                                                                           100 10.5                                                                              11.0                                                                              83.0                                                                              91.0                                                                              0.74                                                                             98.9                                                                              27.5 31.9                                                                              40.6                                                                              83.7                                                                              7                   28 none  none 100 11.0                                                                              9.1 83.1                                                                              93.2                                                                              0.53                                                                             99.4                                                                              30.4 25.7                                                                              43.9                                                                              82.4                                                                              5                   29 NaOH/300                                                                            Kero/600                                                                           100 11.1                                                                              4.7 69.2                                                                              92.7                                                                              0.59                                                                             99.7                                                                              42.1 21.3                                                                              36.6                                                                              89.6                                                                              10                  30 DP/DNP/                                                                             Kero/600                                                                           100 10.8                                                                              11.4                                                                              84.4                                                                              92.4                                                                              0.59                                                                             99.5                                                                              33.3 25.4                                                                              41.3                                                                              85.6                                                                              5                      600                                                                        31 Cresol/600                                                                          Kero/600                                                                           100 10.8                                                                              10.9                                                                              85.2                                                                              94.7                                                                              0.62                                                                             102.1                                                                             28.5 21.5                                                                              50.0                                                                              79.2                                                                              6                   32 SC164p/60                                                                           Kero/600                                                                           100 10.9                                                                              9.6 77.0                                                                              86.3                                                                              0.54                                                                             92.6                                                                              28.1 22.7                                                                              49.2                                                                              80.8                                                                              6                   33 NaOH/300   180 10.7                                                                              36.6                                                                              84.7                                                                              85.3                                                                              0.37                                                                             91.0                                                                              30.9 30.3                                                                              38.8                                                                              86.6                                                                              10                  34 PetHL/                                                                              Kero/600                                                                           100 10.5                                                                              11.5                                                                              89.2                                                                              94.2                                                                              0.48                                                                             100.5                                                                             31.1 17.6                                                                              51.3                                                                              81.0                                                                              6                      600                                                                        35 NP1-15/60                                                                           Dies./600                                                                          100 10.5                                                                              2.5 26.7                                                                              65.5                                                                              2.07                                                                             83.6                                                                              32.5 21.6                                                                              45.9                                                                              88.7                                                                              3                   36 TDA150/                                                                             Kero/600                                                                           100 10.5                                                                              11.6                                                                              81.2                                                                              91.6                                                                              0.50                                                                             98.3                                                                              38.0 23.3                                                                              38.7                                                                              88.7                                                                              3                      60                                                                         37 DP-DNP/                                                                             Kero/600                                                                           100 10.6                                                                              14.1                                                                              88.5                                                                              93.6                                                                              0.34                                                                             99.1                                                                              37.1 25.5                                                                              37.5                                                                              88.4                                                                              2                      600                                                                        38 DP-DNP/                                                                             Kero/600                                                                           100 10.5                                                                              14.7                                                                              90.5                                                                              92.8                                                                              0.34                                                                             98.4                                                                              29.1 33.0                                                                              38.0                                                                              85.3                                                                              2                      300                                                                        39 DP-DNP/                                                                             Kero/600                                                                           130 10.7                                                                              31.8                                                                              83.8                                                                              87.6                                                                              0.40                                                                             93.6                                                                              28.6 36.0                                                                              35.4                                                                              86.6                                                                              4                      600                                                                        40 DP-DNP/                                                                             Kero/600                                                                            80 10.1                                                                              1.6 19.2                                                                              45.1                                                                              3.96                                                                             81.3                                                                              20.1 30.2                                                                              49.7                                                                              87.2                                                                              5                      600                                                                        41 DP-DNP/                                                                             Kero/600                                                                           100 10.5                                                                              12.8                                                                              87.7                                                                              91.6                                                                              0.40                                                                             97.7                                                                              28.6 22.1                                                                              49.4                                                                              80.9                                                                              3                      100                                                                        42 Kero/600   100 10.7                                                                              11.9                                                                              84.6                                                                              91.1                                                                              0.42                                                                             97.1                                                                              31.8 27.1                                                                              41.2                                                                              85.4                                                                              3                   __________________________________________________________________________     Note                                                                          1. Tar sand bitumen concentration, wt %                                       2. Initial separation rate, wt. % of total bitumen recovered per minute       3. Bitumen recovery after 20 minutes of separation, wt % of total bitumen     in feed                                                                       4. Total bitumen recovered, wt % of total bitumen in feed                     5. Concentration of bitumen in sand remaining after extraction, wt %          6. Total bitumen accounted for in product, tailings, and residue on           extraction vessel, % of bitumen in feed. (estimated to                        7. Wt % of sand in feed not separated and recovered in product                8. Subjective evaluation of water quality after 24 hrs. 1 = clear, 5 =        cloudy, 10 = murky, stable sludge, not suitable for recycle              

The information presented in Table VII includes the rates of recovery ofbitumen at different times throughout the separation period. These ratesare expressed as a percentage of the total bitumen present in the feedtar sand. The bitumen remaining in the sand recovered after separationwas measured and is shown in the column labeled "Tail. Bit." and isgiven in wt. % bitumen. The next column in Table VII is labeled "Bit.Mat. Bal" and shown to indicate the comparison between the bitumen inthe tar sand feed and the total bitumen in the recovered product, thetailings sand, and in the residue on the walls of the extraction vessel.In most cases, the material balance on bitumen was excellent andgenerally in the 97% to 103% range. The composition of the productcollected is shown and a calculated value for unrecovered solids or`sand rejection` is also given.

The final column in Table VII is a subjective evaluation of the qualityof the water recovered from the extraction vessel after the separationperiod. The water was collected in quart jars and observed for clarityand suspended solids after approximately 24 hours. The water quality wasrated on a scale of 1 to 10 with 10 being a poor quality sludge such asthat obtained from a hot water caustic run. Any rating of less than 10was judged to be probably acceptable for an internal recycle stream inthe process.

The results of the test runs are also shown in FIGS. 9 through 13. Inthese figures the percentage recovery of bitumen is given as a functionof time. The first twenty-five minutes of the recovery period are shownsince the most dramatic differences between additives occurred duringthis period and since the initial separation rates are likely to be mostimportant in operation of the hydrocyclone. The results are presented inthe order obtained.

EFFECT OF EXTRACTION TEMPERATURE

Based on the results of preliminary experiments, a standard testtemperature of 100° F. was selected for the screening tests. Thisoperating temperature permitted good recovery of bitumen and the abilityto rank the effectiveness of the additives. Three tests were run usingDP-DNP-150 and kerosene at 800° F., 100° F. and 130° F. to evaluate theeffect of temperature on operations. The results of these tests areshown in the following Table VIII and FIG. 14:

                                      TABLE VIII                                  __________________________________________________________________________    Effect of Extraction Temperature on Separation Results                                              Init.                                                                             Recov.  Tail.                                                                            Bit                  Water                                 Feed                                                                              Rate                                                                              @ 20                                                                              Total                                                                             Bit.                                                                             Mat.                                                                              Product Composition                                                                        Sand                                                                              Qual.               Run                                                                              Additive 1/                                                                         Additive                                                                           Temp.                                                                             Conc.                                                                             %/min                                                                             Min Recov.                                                                            %  Bal. %                                                                            Bitumen                                                                            Water                                                                             Solids                                                                            Reject.                                                                           @ 24 Hr             No.                                                                              ppm   2/ppm                                                                              F.  % (1)                                                                             (2) % (3)                                                                             % (4)                                                                             (5)                                                                              (6) wt. %                                                                              wt. %                                                                             wt. %                                                                             %                                                                                 (8)                 __________________________________________________________________________    40 DP-DNP/                                                                             Kero/600                                                                            80 10.1                                                                               1.6                                                                              19.2                                                                              45.1                                                                              3.96                                                                             81.3                                                                              20.1 30.2                                                                              49.7                                                                              87.2                                                                              5                      600                                                                        37 DP-DNP/                                                                             Kero/600                                                                           100 10.6                                                                              14.1                                                                              88.5                                                                              93.6                                                                              0.34                                                                             99.1                                                                              37.1 25.5                                                                              37.5                                                                              88.4                                                                              2                      600                                                                        39 DP-DNP/                                                                             Kero/600                                                                           130 10.7                                                                              31.8                                                                              83.8                                                                              87.6                                                                              0.40                                                                             93.6                                                                              28.6 36.0                                                                              35.4                                                                              86.6                                                                              4                      600                                                                        __________________________________________________________________________     See notes on Tables VI and VII                                           

The operating characteristics of the system vary greatly over thistemperature range. The initial separation rate is especially sensitivein this range, varying from 1.6 to 31.8 min. The total recovery ofbitumen is less sensitive, with results at 100° F. equal to or betterthan the 130° F. results. Depending on the characteristics of thehydrocyclone system, it appears that an operating temperature of 100° F.may be adequate to achieve good results. Significantly poorer resultsare expected to occur as temperature drops below 100° F.

EFFECT OF ADDITIVE CONCENTRATION

For most of the screening tests, additives were added at a rate of 600ppm for chemical #2 surfactant and 600 ppm for either kerosene ordiesel. In one series of tests using DP-DNP-150 and kerosene theconcentration of the DP-DNP-150 component was varied from 0 to 600 ppmwith the kerosene concentration held constant at 600 ppm. The results ofthese tests are shown in the following Table IX and FIG. 15:

                                      TABLE IX                                    __________________________________________________________________________    Effect of DP-DNP-150 Concentration on Separation Results                                            Init.                                                                             Recov.  Tail.                                                                            Bit                  Water                                 Feed                                                                              Rate                                                                              @ 20                                                                              Total                                                                             Bit.                                                                             Mat.                                                                              Product Composition                                                                        Sand                                                                              Qual                Run                                                                              Additive 1/                                                                         Additive                                                                           Temp.                                                                             Conc.                                                                             %/min                                                                             Min Recov.                                                                            %  Bal. %                                                                            Bitumen                                                                            Water                                                                             Solids                                                                            Reject.                                                                           @ 24 Hr             No.                                                                              ppm   2/ppm                                                                              F.  % (1)                                                                             (2) % (3)                                                                             % (4)                                                                             (5)                                                                              (6) wt. %                                                                              wt. %                                                                             wt. %                                                                             %                                                                                 (8)                 __________________________________________________________________________    22-4                                                                             none  Kero/600                                                                           100 10.4                                                                              10.4                                                                              78.7                                                                              90.0                                                                              0.7                                                                              98.1                                                                              27.7 26.7                                                                              45.6                                                                              81.8                                                                              2.5                 41 DP-DNP/                                                                             Kero/600                                                                           100 10.5                                                                              12.8                                                                              87.7                                                                              91.6                                                                              0.4                                                                              97.7                                                                              28.6 22.1                                                                              49.4                                                                              80.9                                                                              3.0                    100                                                                        38 DP-DNP/                                                                             Kero/600                                                                           100 10.5                                                                              14.7                                                                              90.5                                                                              92.8                                                                              0.3                                                                              98.4                                                                              29.1 33.0                                                                              38.0                                                                              85.3                                                                              2.0                    300                                                                        30-3                                                                             DP-DNP/                                                                             Kero/600                                                                           100 10.7                                                                              12.8                                                                              86.4                                                                              93.0                                                                              0.5                                                                              99.3                                                                              35.2 25.4                                                                              39.4                                                                              87.0                                                                              3.5                    600                                                                        __________________________________________________________________________     Notes:                                                                        Runs 22 and 42 averaged for 0 ppm results                                     Runs 30 and 37 averaged for 600 ppm results                                   See notes on Tables VI and VII                                           

As shown the rate of bitumen separation appears to reach a maximum at aconcentration in the 300 ppm range. Total recovery of bitumen and sandrejection, however, tend to increase continuously over the range tested.These results indicate that selection of the optimum additiveconcentration may not be straightforward and may require additionaltests in conjunction with economic evaluations. The trends shown herefor DP-DNP-150 may also be different for other additives.

RANKING OF FLOTATION ADDITIVES

For purposes of selecting additives to be used in the hydrocyclone test,the results of the screening tests were ranked to determine the bestcombinations of additives. The criteria used in the ranking processincluded initial separation rate, total recovery of bitumen, bitumenconcentration in the tailings sand, sand rejection, and water quality.Because the hydrocyclone unit operates over a very brief period, theinitial separation rate was considered an important factor. The totalrecovery of bitumen and the tailings concentration indicated the abilityof the additive to clean bitumen from the tar sand. Maximizing sandrejection is obviously critical and a minimum level of 80% sandrejection was specified. Finally water quality was considered, but ineffect the water quality results from all runs except those in whichcaustic was used are probably acceptable for an internal recycle stream.

The results of the ranking process are given below with the bestadditive combination in each category numbered 1.

    ______________________________________                                             Initial     Total      Tailings                                               Recovery    Recovery   Bitumen  Sand                                     Rank Rate        of Bitumen Content  Rejection                                ______________________________________                                        1.   DP-DNP-     MIBC/      DP-DNP-  TDA150/                                       150/Kero    Diesel     150/Kero Kero                                     2.   MIBC/       Cresol/    CS104/   NP100-150/                                    Diesel      Kero       Kero     Kero                                     3.   TDA150/     DP-DNP-    Kero     DP-DNP-                                       Kero        150/Kero            150/Kero                                 4.   Petronate   MIBC/      MIBC/    NP20/                                         HL/Kero     Kero       Kero     Kero                                     5.   Shurcoal 177/                                                                             CS104/     none     MIBC/                                         Diesel      Kero                Kero                                     ______________________________________                                    

EXAMPLE III

The separation of solids from a tar sand slurry may be accomplishedwithout the use of chemical additives or the introduction of air intothe slurry. The characteristics of this separation process may beillustrated by predicting the recovery of bitumen in the overhead streamproduced by a hydrocyclone to which a tar sand slurry is fed ("TheSizing of Hydrocyclone", R. A. Arterbum, Krebs Engineers).

Such a prediction is shown in FIG. 16 for a tar sand slurry containing30 wt percent of an Athabasca sand with a bitumen content ofapproximately 10 wt percent and in which the bitumen is dispersed withan average droplet size of 30 microns. The separation of bitumen fromthis system is based on the difference between the density of the water,bitumen and solid phases and the enhanced gravitational field producedin the hydrocyclone. The degree of recovery of bitumen depends on thesolids content of the bitumen particles and the quantity of air attachedto the bitumen or within the bitumen droplets. FIG. 16 illustrates thatwith a bitumen solids content of 2 to 5 wt percent and with a bitumenair content of zero, bitumen recoveries of 90 to 95 percent may beachieved.

Pilot test runs using no chemicals demonstrated a bitumen recovery of91%. Separate tests with no air injection into the slurry showed thatexclusion of air from the slurry causes a slight reduction in bitumenrecovery of 4 to 5%. Thus it is possible to conservatively recover >80percent of the bitumen fed to the process without the use of air orchemicals.

EXAMPLE IV

The results of extensive pilot testing using a tar sands slurry feed toa 4 inch Krebs Hydrocyclone is summarized on Table X.

Example IV-1 using 600 ppm of CS85-1 (also described previously asDP-DNP-150, also described as a mixture of ethoxylated dodecyl phenoland dinonyl phenol with 150 ethoxylated groups) and 600 ppm of keroseneresulted in a feed bitumen to product recovery of 91.4 percent.

Examples IV-2 through IV-5 show the effect of the chemical CS 85-1 andindicate an incremental increase of feed bitumen to product of 5.0%,7.4%, 2.9% and 2.7%.

Examples IV-6 shows the effects of adding 600 ppm of MIBC(methyl-isobutyl-carbinol) to the tar sands slurry feed and results inan incremental increase of feed bitumen to product of 1.6%.

Example IV-7 shows the effects of adding 600 ppm of CS83 (a 50/50mixture of NP40 and NP100) to the tar sands slurry feed and results inan incremental increase of feed bitumen to product of 4.1%.

Example IV-8 shows the effects of adding 400 ppm of Petronate HL(described previously as a petroleum sulfonate sold under the trademarkWITCO Petronate HL) and 400 ppm of Kerosene to the tar sands slurry feedand results in an incremental increase of feed bitumen to product of6.0%.

Example IV-9 shows the effects of adding 600 ppm of SC-177 (describedpreviously as a C₆ to C₉ branched aliphatic alcohol and/or ketones soldunder the trademark Sherex Shurcoal 177) and 600 ppm of kerosene to thetar sands slurry feed and results in an incremental increase of feedbitumen to product of 7.7%.

Example IV-10 shows the effects of adding 450 ppm of calciumlignosulfonate (sold under the trade name Lignosite Road Binder 50% byGeorgia-Pacific) and 450 ppm of kerosene to the tar sands slurry feedand results in an incremental increase of feed bitumen to product of2.3%.

Examples IV-11 and IV-12 show the effect of including air injection,i.e., increasing air from 0 to 2.5 SCFM to the tar sands slurry feed andresults in an incremental increase of feed bitumen to product of 7.7% to12.5% and 3.8% respectively.

Example IV-13 shows the effect of increasing tar sands slurry feedtemperature from 42° C. to 59° C. on bitumen recovery and results in anincremental increase of feed bitumen to product of 4.3%.

Example IV-14 shows the effects of increasing tar sands slurry feedconcentration. Increasing slurry concentration from 20% to 40% reducesbitumen recovery by approximately 10%.

Example IV-15 shows the effects of the mixer position in the feed loop.Bitumen recovery improves by 2.1% after moving the mixer closer to thetumbler position i.e., upstream of the 100 foot loop.

Example IV-16 shows the effect of a 100 foot length of pipe in the feedto the hydrocyclone. Adding 100 feet of piping improves tar sands slurrymixing and improves bitumen recovery by 6.0%.

Example IV-17 shows that bitumen recovery is insensitive to slurry flowrate over the range tested.

                                      TABLE X                                     __________________________________________________________________________    EXAMPLE IV -- RESULTS AND SUMMARY OF PILOT PLANT TESTING OF 4 INCH KREBS      HYDROCYCLONE                                                                  Example                 Run   Chemical                                                                             Chemical                                                                           Feed Bitumen                        Number                                                                             Objective          Number                                                                              1/ppm  2/ppm                                                                              to Product                                                                           Comments                     __________________________________________________________________________    EFFECTS OF CHEMICALS                                                          IV-1 Determine Bitumen  1     CS 85-1/600                                                                          Kero/600                                                                           91.4%  Used tar sand #1                  Recovery with CS 85-1                                                    IV-2 Determine effect of                                                                              9 thru 17                                                                           0      Kero/600                                                                           79.4   CS85-1 gives 5.0%                                                             greater                           CS 85-1            18 thru 20                                                                          CS85-1/300                                                                           Kero/600                                                                           84.4   recovery                     IV-3 Determine effect of                                                                              51    0      Kero/600                                                                           76     CS85-1 gives 7.4%                                                             greater                           CS 85-1            49 + 53                                                                             CS85-1/250                                                                           Kero/600                                                                           83.4   recovery                     IV-4 Determine effect of                                                                              57    0      0    80.5   CS85-1 without Kero                                                           gives                             CS 85-1            55 + 58                                                                             CS85-1/200                                                                           0    83.4   2.9% greater recovery        IV-5 Determine effect of                                                                              66    0      0    90.9   CS85-1 with Kero gives            CS 85-1            67,68,69,72                                                                         CS85-1/300                                                                           Kero/600                                                                           93.6   2.7% greater recovery        IV-6 Determine effect of                                                                              35,36 0      Kero/600                                                                           78.7   MIBC gives 1.6% greater           MIBC               37,38 MIBC/600                                                                             Kero/600                                                                           80.3   recovery                     IV-7 Determine effect of                                                                              43    0      Kero/600                                                                           85.9   CS83 gives 4.1% greater           CS 83              45-48 CS83/600                                                                             Kero/600                                                                           90.0   recovery                     IV-8 Determine effect of                                                                              73    0      0    84.1   Petronate HL + Kero               Petronate HL       74,75 Pet HL/400                                                                           Kero/400                                                                           90.1   give 6% greater                                                               recovery                     V-9  Determine effect of                                                                              86    0      0    83.8   SC-177 + Kero gives               SC-177             82,83 SC-177/600                                                                           Kero/600                                                                           91.5   7.7% greater recovery        IV-10                                                                              Determine effect of                                                                              88    0      0    83.7   Calcium Lignosulfonate                                                        +                                 Calcium Lignosulfonate                                                                           89,90 Ligno/450                                                                            Kero/450                                                                           86     Kero gives 2.3% greater                                                       recovery                     Effects of Air                                                                IV-11                                                                              Determine effect of                                                                       0   SCFM                                                                             13    0      Kero/600                                                                           70.4   Including air raised                                                          bitu-                             Air Injection                                                                             2.5 SCF                                                                              14-17 0      Kero/600                                                                           82.9   men recovery by 7.7 to                        2.5 SCF                                                                              9-12  0      Kero/600                                                                           78.1   12.5%                        IV-12                                                                              Determine effect of                                                                       2.5 SCFM                                                                             63    CS 83/200                                                                            Kero/600                                                                           90.6   Increasing air from 0                                                         to                                Air Injection                                                                             0   SCFM                                                                             64    CS 83/200                                                                            Kero/600                                                                           86.8   2.5 SCFM increased                                                            bitu-                                                                         men recovery by 3.8%         Effects of Temperature                                                        IV-13                                                                              Determine effect of                                                                       42° C.                                                                        87     SC-177/600                                                                          Kero/600                                                                           88     Increasing temperature                                                        in-                               treating temperature                                                                      53° C.                                                                        83    SC-177/600                                                                           Kero/600                                                                           90.7   creases bitumen                                                               recovery,                                     59° C.                                                                        82    SC-177/600                                                                           Kero/600                                                                           92.3   i.e., Δ17°                                                       C. = 4.3%                    Effects of Concentration                                                                       Conc. %                                                      IV-14                                                                              Determine effect of                                                                       20     30    CS 85-1/300                                                                          Kero/600                                                                           88.3   Increasing slurry                                                             concen-                           tar sand slurry concen-                                                                   25     31    CS 85-1/300                                                                          Kero/600                                                                           88.4   tration from 20 to 40%                                                        re-                               tration to FSU                                                                            30     32    CS 85-1/300                                                                          Kero/600                                                                           89.1   duces bitumen recovery                        35     33    CS 85-1/300                                                                          Kero/600                                                                           83.8   approximately 10%                             40     34    CS 85-1/300                                                                          Kero/600                                                                           78.7                                Effects of Mixer Position                                                     IV-15                                                                              Determine effects of                                                                      After Loop                                                                           79    CS 85-1/300                                                                          Kero/600                                                                           90     Recovery improves by              mixer position                                                                            Before Loop                                                                          76    CS 85-1/300                                                                          Kero/600                                                                           92.1   moving the mixer closer                                                       to                                                                            the tumbler i.e.,                                                             up-stream                                                                     of the loop                  Effects of Length of Piping on Mixing                                         IV-16                                                                              Determine effect length                                                                   No Loop                                                                               16   0      Kero/600                                                                           80.2   100 feet of piping                                                            improves                          of pipe has on mixing                                                                     100 ft.                                                                              17    0      Kero/600                                                                           86.2   the bitumen recovery by                                                       6.0%                         Effects of Flow Rate                                                          IV-17                                                                              Determine effect of                                                                       16.3 GPM                                                                             5     CS 85-1/300                                                                          Kero/600                                                                           89.6   Bitumen recovery is                                                           insen-                            Slurry Flow Rate                                                                          20.1 GPM                                                                             8     CS 85-1/300                                                                          Kero/600                                                                           88.2   sitive to slurry flow                                                         rate                                          16.5   9-11  0      Kero/600                                                                           78.8   over range tested                             20.4   16    0      Kero/600                                                                           80.2                                __________________________________________________________________________

EXAMPLE V

FIG. 17 illustrates a process option in which the benefits of theinvention are achieved with minimum capital investment and operatingcosts. The objective of this option is to reduce the sand content of atar sand feed to a central processing plant by removing the bulk of thesand at a remote mine site. The bitumen retained in the sand reductionprocess is then transported to the central processing plant asbitumen/water stream containing 50% to 90% water by weight.

This process option incorporates two primary components: (1) SlurryPreparation and (2) Primary Separation. The slurry preparation step isidentical to that described in Example 1 and involves mixing of the rawtar sand with water and chemicals and heating to the desired operatingtemperature followed by agitation.

Slurry preparation is followed by injection of air into the slurry,mixing in a pipeline or mixer and injected into the primary separationunits. In these units the bulk of the sand particles are rejected as atailings stream and the bitumen is retained with the water used toprepare the slurry. The separated bitumen/water stream is then pumped tothe central processing plant which uses conventional technology forbitumen-water separation. The recovered water may be heated and recycledto the remote sand reduction process for further use in slurrypreparation.

The following Table XI illustrates typical rates for a system with afeed note of 1000 tons/day of tar sand to the process depicted in FIG.17.

                                      TABLE XI                                    __________________________________________________________________________               FLOW RATES, LBS/HR                                                            1    2    3    7    13   14                                                   Tar Sand                                                                           Tar Sand                                                                           Bitumen/                                                                           FSU  Recycle                                                                            Make-up                                              Feed Slurry                                                                             Water                                                                              Tails                                                                              Water                                                                              Water                                     __________________________________________________________________________    Tar Sand, (tons/day)                                                                     1000                                                               Bitumen    8467 8467 7620  847                                                Solids > 44 microns                                                                      67189                                                                              67189                                                                              2016 65173                                               Solids < 44 microns                                                                      4061 4061 3574  487                                                Water      3617 119575                                                                             54761                                                                              64814                                                                              54761                                                                              61197                                     Total      83333                                                                              199292                                                                             67971                                                                              131321                                                                             54761                                                                              61197                                     __________________________________________________________________________

While the present invention has been described herein with reference toparticular embodiments thereof, a latitude of modification, variouschanges and substitutions are intended in the foregoing disclosure, andit will be appreciated that in some instances some features of theinvention will be employed without a corresponding use of other featureswithout departing from the scope of the invention as set forth.

We claim:
 1. A process for recovering a hydrocarbon from a hydrocarbonbearing sand comprising the steps of:(a) mixing a chemical additive witha chemical composition and with a hydrocarbon bearing sand containinghydrocarbon and residual solids including clay, at a temperature to forma slurry, wherein said chemical composition comprises an aqueous phaseand a minor amount of a chemical agent selected from the groupconsisting of at least one ethoxylated alkylphenol compound, at leastone ethoxylated dialkylphenol compound and mixtures thereof; (b)aerating the formed slurry of step (a) to a rate ranging from about 0.1SCF of air per gallon of formed slurry to about 1.0 SCF of air pergallon of formed slurry to produce essentially sludge-free tailings anda mixture of hydrocarbon, aqueous phase and residual solids includingclay not containing a sodium ion; (c) separating with an enhancedgravity separator said mixture of said hydrocarbon, said aqueous phaseand said residual solids including clay from the essentially sludge-freetailings.
 2. The process of claim 1 whereinsaid chemical agent comprisesat least one ethoxylated alkylphenol compound having the generalformula: ##STR11## wherein n₁ is an integer having a value of from about7 to about 20, and y₁ is an integer having a value of from about 4 toabout 1000; and said at least one ethoxylated alkylphenol compound has amolecular weight distribution with a dispersity of from about 1.0 toabout 5.0 and with a weight average molecular weight of from about 1966to about 9188; and wherein at lest about 50% by weight of the chemicalagent comprises said at least one ethoxylated alkylphenol compoundhaving a molecular weight of from about 1966 to about
 9188. 3. Theprocess of claim 2 wherein from 1% by weight to 90% by weight of thechemical agent comprises said at least one ethoxylated alkylphenolcompound wherein y₁ has a value greater than
 100. 4. The process ofclaim 1 wherein said chemical agent comprises from about 30% by weightto about 80% by weight of said at least one ethoxylated alkylphenolcompound, and said chemical agent additionally comprises at least oneethoxylated dialkylphenol compound having the general formula: ##STR12##wherein n₂ is an integer having a value of from about 7 to about 18, andn₃ is an integer having a value of from about 7 to about 18, and y₂ isan integer having a value of from about 4 to about 1000; and whereinsaid at least one ethoxylated dialkylphenol compound and said at leastone ethoxylated alkylphenol compound have a molecular weightdistribution with a dispersity of from about 1.0 to about 5.0 and with aweight average molecular weight of from about 1966 to about 11,627; andwherein at least about 50% by weight of the chemical agent comprisessaid at least one ethoxylated alkylphenol compound having at least oneethoxylated dialkylphenol compound having a molecular weight of fromabout 2519 to about 11,627; and from 1% by weight to 90% by weight ofthe chemical agent comprises said at least one ethoxylated dialkylphenolcompound wherein y₂ is greater than
 100. 5. The process of claim 1wherein said separating step (c) comprises introducing the producedessentially sludge-free tailings and produced mixture of hydrocarbon,aqueous phase, and residual solids including clay into a hydrocyclone.6. The process of claim 1 additionally comprising heating said aqueousphase prior to mixing said chemical additive with said hydrocarbonbearing sand.
 7. The process of claim 1 additionally comprisingseparating said aqueous phase from said residual solids including clayand recycling said separated aqueous phase for admixing with saidchemical additive and with said emulsifying composition and with saidhydrocarbon bearing sand.
 8. The process of claim 1 additionallycomprising agitating said formed slurry of step (a) prior to saidaerating step (b).
 9. The process of claim 8 additionally comprisingagitating said aerated slurry of step (b) prior to said separating step(c).
 10. The process of claim 1 wherein said chemical additive isselected from the group consisting of kerosene, diesel oil and mixturesthereof.
 11. A process for recovering bitumen from tar sands comprisingthe steps of:(a) mixing a chemical additive with a chemical agent andwith an aqueous phase and with tar sands containing bitumen and residualsolids including clay, at a temperature to form a slurry, wherein saidchemical agent is selected from the group consisting of at least oneethoxylated alkylphenol compound, at least one ethoxylated dialkylphenolcompound and mixtures thereof; (b) pumping the formed slurry of step (a)towards at least one mixer; (c) aerating the pumped slurry of step (b)with air at a rate ranging from about 1 to about 20 SCF of air/minute toassist in the production of essentially sludge-free tailings and amixture of bitumen, aqueous phase and residual solids including clay;(d) agitating the aerated slurry of step (c) with said at least onemixer to further assist in the produce of essentially sludge-freetailings and said mixture of bitumen, aqueous phase and residual solidsincluding clay not containing a sodium ion; (e) separating with at leastone first separator said mixture of said bitumen and said aqueous phaseand said residual solids including clay from the agitated slurry of step(d) to produce essentially sludge-free tailings; and (f) separating saidaqueous phase and said residual solids including clay from said step (e)mixture comprising said bitumen, said residual solids including clay,and said aqueous phase to produce said bitumen as being essentially freeof residual solids including clay.
 12. The process of claim 11 whereinsaid chemical agent comprises at least one ethoxylated alkylphenolcompound having the general formula: ##STR13## wherein n₁ is an integerhaving a value of from about 7 to about 20, and y₁ is an integer havinga value of from about 4 to about 1000; and said at least one ethoxylatedalkylphenol compound has a molecular weight distribution with adispersity of from about 1.0 to about 5.0 and with a weight averagemolecular weight of from about 1966 to about 9188; and wherein at leastabout 50% by weight of the chemical agent comprises said at least oneethoxylated alkylphenol compound having a molecular weight of from about1966 to about
 9188. 13. The process of claim 11 wherein said chemicalagent comprises from about 30% by weight to about 80% by weight of saidat least one ethoxylated alkylphenol compound, and said chemical agentadditionally comprises at least one ethoxylated dialkylphenol compoundhaving the general formula: ##STR14## wherein n₂ is an integer having avalue of from about 7 to about 18, and n₃ is an integer having a valueof from about 7 to about 18, and y₂ is an integer having a value of fromabout 4 to about 1000; and wherein said at least one ethoxylateddialkylphenol compound and said at least one ethoxylated alkylphenolcompound have a molecular weight distribution with a dispersity of fromabout 1.0 to about 5.0 and with a weight average molecular weight offrom about 1966 to about 11,627; and wherein at least about 50% byweight of the chemical agent comprises said at least one ethoxylatedalkylphenol compound having at least one ethoxylated dialkylphenolcompound having a molecular weight of from about 2519 to about 11,627;and from 1% by weight to 90% by weight of the chemical agent comprisessaid at least one ethoxylated dialkylphenol compound wherein y₂ isgreater than
 100. 14. A process for the extraction and recovery of ahydrocarbon from water wet tar sands comprising:(a) introducing a waterwet tar sand and water into a conditioning zone to form a tar sandslurry; (b) agitating the formed tar sand slurry of step (a) to form anagitated tar sand slurry; (c) aerating the formed agitated tar sandslurry to form an aerated tar sand slurry comprising water, hydrocarbonand solids; and (d) separating in less than about five secondsessentially all of the solids from the hydrocarbon and water of theaerated tar sand slurry to produce a hydrocarbon and water mixturecomprising residual solids; and (e) separating essentially all of thehydrocarbon and residual solids from the hydrocarbon and water mixtureof step (d); and (f) introducing said produced hydrocarbon and residualsolids of step (e) into an upgrading unit.
 15. The process of claim 14wherein said separating step (d) comprises introducing the aerated tarsand of step (c) directly into a hydrocyclone without passing theaerated tar sand through a flotation cell.
 16. The process of claim 15wherein said tar sand slurry of step (a) contains no pH controllingagent.
 17. The process of claim 14 additionally comprising introducing achemical additive into the conditioning zone of step (a) along with thewater wet tar sand and the water.
 18. The process of claim 17 whereinone of the chemical additives is selected from a group consisting ofMIBC, SC-177, Petronate HL, Calcium Lignosulfonate, CS 104, DP-DNP-150;and a second chemical additive is from kerosene and/or diesel.
 19. Theprocess of claim 14 additionally comprising introducing said separatedhydrocarbon into a primary separator.
 20. The process of claim 14 inwhich the tar sand slurry of step (a) is aerated by injection ofpressurized water saturated with air.
 21. The process of claim 19 inwhich the solids separated in step (c) is deposited at a tar sand minesite.
 22. The process of claim 14 wherein said separating step (d)comprises introducing the aerated tar sand of step (c) directly into ahydrocyclone.
 23. The process of claim 14 additionally comprisingadmixing a chemical additive with the tar sand slurry of step (a), saidchemical additive being selected from a group consisting of MICB,SC-177, Petronate HL, Calcium Lignosulfonate, CS 104, DP-DNP-150,kerosene diesel, and mixtures thereof.
 24. A process for recovering ahydrocarbon from a hydrocarbon bearing sand comprising the steps of:(a)mixing a chemical additive with a chemical composition and with ahydrocarbon bearing sand containing hydrocarbon and residual solidsincluding clay, at a temperature to form a slurry, wherein said chemicalcomposition comprises an aqueous phase and a minor amount of a chemicalagent selected from the group consisting of at least one ethoxylatedalkylphenol compound, at least one ethoxylated dialkylphenol compoundand mixtures thereof; (b) aerating the formed slurry of step (a) toproduce essentially sludge-free tailings and a mixture of hydrocarbon,aqueous phase and residual solids including clay, said residual solidsincluding clay in said mixture does not contain a sodium ion fromcaustic; (c) separating said mixture of said hydrocarbon, said aqueousphase and said residual solids including clay from the essentiallysludge-free tailings.
 25. The process of claim 24 additionallycomprising separating said step (c) mixture to produce hydrocarboncontaining minor amounts of clays and aqueous phase; and upgrading saidproduced hydrocarbon containing minor amounts of clays and aqueousphase.
 26. A process for recovering a hydrocarbon from a hydrocarbonbearing sand comprising the steps of:(a) mixing a chemical additive witha chemical composition and with a hydrocarbon bearing sand containinghydrocarbon and residual solids including clay, at a temperature to forma slurry, wherein said chemical composition comprises an aqueous phaseand a minor amount of a chemical agent selected from the groupconsisting of at least one ethoxylated alkylphenol compound, at leastone ethoxylated dialkylphenol compound and mixtures thereof; (b)aerating the formed slurry of step (a) to produce essentiallysludge-free tailings and a mixture of hydrocarbon, aqueous phase andresidual solids including clay; (c) separating said mixture of saidhydrocarbon, said aqueous phase and said residual solids including clayfrom the essentially sludge-free tailings; (d) separating said step (c)mixture to produce hydrocarbon containing minor amounts of clays andaqueous phase; and (e) upgrading said produced hydrocarbon containingminor amounts of clays and aqueous phase.
 27. A process for recoveringbitumen from tar sands comprising the steps of:(a) mixing a chemicaladditive with an aqueous phase sand with tar sands containing bitumenand residual solids including clay, at a temperature to form a slurry;(b) pumping the formed slurry of step (a) towards at least one mixer;(c) aerating the pumped slurry of step (b) to assist in the productionof essentially sludge-free tailings and a mixture of bitumen, aqueousphase and residual solids including clay; (d) agitating the aeratedslurry of step (c) with said at least one mixer to further assist in theproduce of essentially sludge-free tailings and said mixture of bitumen,aqueous phase and residual solids including clay; (e) separating with atleast one first separator said mixture of said bitumen and said aqueousphase and said residual solids including clay from the agitated slurryof step (d) to produce essentially sludge-free tailings having residualbitumen and water; and (f) passing said essentially sludge-free tailingshaving residual bitumen and water into at least one second separator toseparate residual bitumen and water from the sludge-free tailings andproduce coarse solids; (g) admixing said residual bitumen and water ofstep (f) with said mixture of said bitumen, said aqueous phase and saidresidual solids including clay to produce an admixture; and (h) passingsaid admixture of step (g) into a third separator to separate saidadmixture and produce bitumen as being essentially free of residualsolids including clay, and water and fines.
 28. The process of claim 27additionally comprising upgrading said produced step (h) bitumen asbeing essentially free of residual solids including clay.
 29. Theprocess of claim 28 additionally comprising passing the water and finesinto a fourth separator to separate fines from the water.
 30. Theprocess of claim 29 additionally comprising admixing the coarse solidsof step (f) with the separated fines and disposing the coarse solids andseparated fines.
 31. The process of claim 30 additionally comprisingadmixing the separated water with the aqueous phase of step (a).
 32. Theprocess of claim 27 additionally comprising passing the water and finesinto a fourth separator to separate fines from the water.
 33. Theprocess of claim 32 additionally comprising admixing the separated waterwith the aqueous phase of step (a).
 34. The process of claim 33additionally comprising admixing the separated water with the aqueousphase of step (a).
 35. A process for recovering a hydrocarbon from ahydrocarbon bearing sand comprising the steps of:(a) mixing a chemicaladditive with a chemical composition and with a hydrocarbon bearing sandcontaining hydrocarbon and residual solids including clay, at atemperature to form a slurry, wherein said chemical compositioncomprises an aqueous phase and a minor amount of a chemical agentselected from the group consisting of at least one ethoxylatedalkylphenol compound, at least one ethoxylated dialkylphenol compoundand mixtures thereof; (b) aerating the formed slurry of step (a) toproduce essentially sludge-free tailings and a mixture of hydrocarbon,aqueous phase and residual solids including clay; (c) separating saidmixture of said hydrocarbon, said aqueous phase and said residual solidsincluding clay from the essentially sludge-free tailings; (d) separatingsaid aqueous phase and said residual solids including clay form saidstep (c) mixture comprising said hydrocarbon, said residual solidsincluding clay, and said aqueous phase to produce said hydrocarbon asbeing essentially free of residual solids including clay; and (e)upgrading said produced hydrocarbon being essentially free of residualsolids including clay.
 36. The process of claim 35 wherein saidseparating step (c) comprises introducing the produced essentiallysludge-free tailings and produced mixture of hydrocarbon, aqueous phase,and residual solids including clay into a hydrocyclone.
 37. The processof claim 35 additionally comprising heating said aqueous phase prior tomixing said chemical additive with said hydrocarbon bearing sand. 38.The process of claim 35 wherein said residual solids including clay insaid mixture of step (b) does not contain a sodium ion.
 39. The processof claim 35 additionally comprising separating said aqueous phase fromsaid residual solids including clay and recycling said separated aqueousphase for admixing with said chemical additive and with said emulsifyingcomposition and with said hydrocarbon bearing sand.
 40. The process ofclaim 35 additionally comprising agitating said formed slurry of step(a) prior to said aerating step (b).
 41. The process of claim 40additionally comprising agitating said aerated slurry of step (b) priorto said separating step (c).
 42. The process of claim 35 wherein saidchemical additive is selected from the group consisting of kerosene,diesel oil and mixtures thereof.